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EXERCISES IN 

MENTAL 
ARITHMETIC 



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MIRICK- BALLOU-TALL 



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LIBRARY 



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PRACTICE EXERCISES IN 
MENTAL ARITHMETIC 



BY 

GEORGE A. MIRICK 

IN8TBUOTOB IN EDUCATION, HARVARD UNIVERSITY 

FORMERLY ASSISTANT COMMISSIONER OF EDUCATION 

STATE OF NEW JERSEY 



FRANK W. BALLOU 

SUPERINTENDENT OF PUBLIC SCHOOLS 
DISTRICT OF COLUMBIA 

AND 

LIDA LEE TALL 

PRINCIPAL OF THE MARYLAND STATE NORMAL SCHOOL 
TOWSON, MARYLAND 



GINN AND COMPANY 

BOSTON • NEW YORK • CHICAGO • LONDON 
ATLANTA • DALLAS • COLUMBUS • SAN FRANCISCO 



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MityATi tciooL or t ducatmI 



HarvardxUnivpfgity, 

Library of theGi^duate School 

of^mjcation 



COPYRIGHT, 1920, BY 

GEORGE A. MIRICK, FRANK W. BALLOU 
, AND LIDA LEE TALL 



ALL RIGHTS RESERVED 
221.6 



GINN AND COMPANY • PRO- 
PRIETORS • BOSTON • U.S.A. 



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PREFACE 

There are difficulties that retard the progress of children in their 
study of arithmetic \^hich until recently were not recognized and 
are now too little considered by teachers. Dr. Charles H. Judd, 
in his report on the Survey of the St. Louis Public Schools, points 
to those in abstract arithmetic in these words : 

It is a mistake to assume, for example, that addition is a single 
process in all of its different applications. The fact is that addition 
and all of the other arithmetical operations are among the most com- 
plex subjects in the course of study. Children have a great deal of 
difficulty with arithmetic because teachers do not understand the 
special difficulties which are encountered by individual children at 
different stages of their training. 

In " How to Teach," by Strayer and Norsworthy, attention 
is called to this matter, as follows: 

Investigation seems to give evidence that in the habit of simple 
column addition eight or nine different functions are involved, each 
of which involves the use of several bonds. Besides these positive 
connections a child in learning must inhibit other connections which 
are incorrect, and these must often outnumber the correct ones. And 
yet column addition has always been treated as a simple habit, with 
perhaps one element of complexity, when carrying was involved. It 
is evident that if the habit concerned does involve eight or nine 
different functions, a child might go astray in any one. 

The mental difficulties that children meet in their study of 
arithmetic are not confined to abstract calculation. There are 
complexities no less troublesome when they solve problems. 

iii 

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iv PRACTICE EXERCISES IN MENTAL ARITHMETIC 

They must understand the situations in which the problems lie ; 
they must exercise mathematical judgment to determine the 
processes to be used, and in many instances to choose one of 
two or three possible methods of solution ; they must interpret 
the meaning of the language with which the problem is stated. 

It seems to the authors that these parallel lines of difficulty 
are best overcome by giving special training in meeting each 
kind separately. Thiey also believe that systematic training in 
both lines should begin not later than the third grade, that it 
should deal with the simple, fundamental arithmetical facts and 
the common types of problems, and that this training should 
have for its purpose the development of mathematical facility 
and skill. 

The following characteristics of this book are in harmony 
with these convictions: 

1. The exercises in abstract calculation have been separated from 
the exercises in problem solving, a page of the one following a page 
of the other. 

The relation between the two series of exercises is close, in that 
the problems of each exercise involve the processes and combinations 
studied on the preceding page of abstract exercises, except the two 
pages of miscellaneous problems placed at the end of each quarter's 
work. 

2. All the whole-number combinations essential to success in 
elementary arithmetic have been included in these exercises. 

3. Repeated reviews of troublesome combinations are provided 
according to their relative degree of difficulty. 

4. To guide teachers in the use of the exercises detailed direc- 
tions are to be found on nearly every page. 

5. The problems on each page deal with one familiar situation 
(except in the case of the miscellaneous problems). This leads to 
more sustained thinking in each phase of the daily life in which 
arithmetic is applied. 

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PREFACE V 

6. The problems have been stated in all the different ways in 
which children are likely to meet them. Language difficulties have 
been carefully removed. 

7. Emphasis is placed on the making of original problems by the 
pupils themselves. This exercise will train them to study their sur- 
roundings, to see their school arithmetic in its everyday use, and 
to apply their knowledge and skill gained in school to situations 
out of school. 

The authors wish to acknowledge their indebtedness to 
Dr. Harry V. HoUoway's " Experimental Study to Determine 
the Relative Difl&culty of the Elementary Combinations in 
Addition and Multiplication." This study was made in 1918 
and 1914, under the direction of the School of Education of 
the University of Pennsylvania, and its findings have .been used 
as a guide in the selection of troublesome combinations. 

The authors are under obligation, also, to the superintendents 
of the schools of Boston, of Cambridge, and of Arlington, 
Massachusetts, for permission to make trial of the exercises in 
the schools under their direction, and to the ^teachers who used 
with their pupils the first prepared exercises. In the light of 
these trials with a large number of pupils the exercises have 
been thoroughly revised. 



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CONTENTS 

PAGE 

Suggestions to Teachers xi 

GRADE III. FIRST SERIES 

EXERCISES 

I-III. Addition: Numbers 0-9 2 

IV. Problems : At Home (Addition) 3 

V-VII. Addition : One and Two-Figure Numbers, Sums to 20 . . . 4 

VIII. Problems : At Home (Addition) 6 

IX-XI. Subtraction : Numbers 0-9 6 

XII. Problems : At Home (Subtraction) 7 

XIII-XV. Subtraction: Numbers 0-19 8 

XVI. Problems : At Home (Subtraction) 9 

XVII-XIX. Multiplication : Numbers 1-10 10 

XX. Problems : At Home (Multiplication) 11 

XXI-XXIII. Division : Even Quotients, Dividends to 100 12 

XXIV. Problems : At Home (Division) 13 

XXV. Problems : Miscellaneous 14 

XXVI. Problems: Miscellaneous 15 

GRADE III. SECOND SERIES 

I-III. Addition : By Endings, No Carrying 16 

IV. Problems : At Play (Addition) 17 

V-VII. Addition : Review, Troublesome Combinations 18 

VIII. Problems : At Play (Addition) 19 

IX-XI. Subtraction : By Endings, No Borrowing 20 

XII. Problems : At Play (Subtraction) 21 

XIII-XV. Subtraction : Review, Troublesome Combinations 22 

XVI. Problems : At Play (Subtraction) 23 

XVII-XIX. Multiplication : Products to 100 24 

XX. Problems : At Play (Multiplication) 25 

XXI-XXIII. Division : Divisors 2-9, Dividends to 100 26 

XXIV. Problems : At Play (Division) 27 

XXV. Problems: Miscellaneous 28 

XXVI. Problems: Miscellaneous 29 

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viii PRACTICE EXERCISES IN MENTAL ARITHMETIC 
GRADE III. THIRD SERIES 

BXSBCI8BS PAGB 

I-III. Addition : Two-Figure Numbers 30 

IV. Problems : At School (Addition) 31 

V-VII. Subtraction : Two-Figure Numbers 32 

VIII. Problems : At School (Addition) 83 

IX-XI. Addition: Two-Figure Numbers 34 

XII. Problems : At School (Addition) 36 

XIII-XV. Subtraction : Two-Figure Numbers 36 

XVI. Problems : At School (Subtraction) 37 

XVII-XIX. Multiplication: Remew 38 

XX. Problems : At School (Multiplication) 39 

XXI-XXIII. Division: ReHew 40 

XXIV. Problems : At School (Multiplication) 41 

XXV. Problems: Miscellaneous 42 

XXVI. Problems : Miscellaneous 43 

GRADE III. FOURTH SERIES 

I-III. Addition : United States Money, Two-Figure Numbers . . 44 

IV. Problems : Earning, Saving, and Spending (Addition) ... 46 

V-VII. Addition : United States Money, Two-Figure Numbers . . 46 

VIII. Problems : Earning, Saving, and Spending (Addition) ... 47 

IX-XI. Subtraction : United States Money, Two-Figure Numbers . 48 

XII. Problems : Earning, Saving, and Spending (Subtraction) . 49 

XIII-XV. Multiplication : United States Money, One- and Two-Figure 

Numbers 60 

XVI. Problems : Earning, Saving, and Spending (Multiplication) . 61 

XVII-XIX. Multiplication : United States Money, Troublesome to 12 x 9 52 

XX. Problems : Earning, Saving, and Spending (Multiplication) . 63 

XXI-XXIII. Division : Even Parts of Cents 54 

XXIV. Problems : Earning, Saving, and Spending (Division) ... 56 

XXV. Problems: Miscellaneous 66 

XXVI. Problems: Miscellaneous 67 

GRADE IV. FIRST SERIES 

To Teachers 68 

Tables op Measurements 69 



I. Reading Numbers : 100-999 60 

II, III. Addition : Three One-Figure Numbers 60 

IV. Problems : At Home (Addition) 61 

V. Reading Numbers : I-L 62 

VI, VII. Addition : Three One-Figure Numbers 62 

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CONTENTS 



IX 



BZBBCISES PAGE 

VIII. Problems : At Home (Addition) ........... 63 

IX. Counting : By 2's, 3's, 4's, 6's, to 100 .... ^ .... 64 

X, XI. Subtraction : Beview by Endings 64 

XII. Problems : At Home (Subtraction) 65 

XIII. Reading Numbers : United States Money to $10 66 

XIV, XV. Multiplication : Review, Easily Forgotten Combinations . . 66 

XVI. Problems : At Home (Multiplication) 67 

XVII. Reading Numbers : United States Money to |100 .... 68 

XVni, XIX. Multiplication : By 10, 20, 100, etc 68 

XX. Problems : At Home (Multiplication) 69 

XXI. Reading Numbers : United States Money to |1000 .... 70 

XXII, XXIII. Division : Divisor and Dividend Ending in Zero .... 70 

XXIV. Problems : At Home (Division) 71 

XXV. Problems: Miscellaneous 72 

XXVI. Problems: Miscellaneous 73 

GRADE IV. SECOND SERIES 

I. Reading Numbers : 1000-5000 74 

II, III. Addition : United States Money to |10 74 

IV. Problems : At School (Addition) 75 

V. Reading Numbers : LI-C . ^ 76 

VI, VII. Addition: United States Money to $100 . 76 

VIII. Problems : At School (Addition) 77 

IX. Counting by 6's and 7's to 100 78 

X, XI. Subtraction : Troublesome Combinations 78 

XII. Problems : At School (Subtraction) 79 

XIII. Counting : By 8's and 9's to 100 80 

XIV, XV. Multiplication : Review 80 

XVI. Problems : At School (Multiplication) 81 

XVII. Counting : By ll's and 12's to 100 82 

XVIII, XIX. Multiplication : Review 82 

XX. Problems : At School (Multiplication) 83 

XXI. Reading Numbers : Common Fractions 84 

XXII, XXIII. Division : Two Types of Division 84 

XXIV. Problems : At School (Division) 86 

XXV. Problems: Miscellaneous 86 

XXVI. Problems: Miscellaneous 87 

GRADE IV. THIRD SERIES 

I. Reading Numbers : Mixed Numbers 88 

II, III. Fractional Parts : i, J, J of Numbers to 100 88 

IV. Problems : At the Newsdealer's Store 89 



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PKACTICE EXEECISES IN MENTAL ARITHMETIC 



EXERCISES 

V. Counting: 

VI, VII. Measures : 

VIII. Problems: 

IX. Counting: 

X, XI. Measures : 

XII. Problems: 

XIII. Measures : 

XIV. Measures : 
XV. Measures : 

XVI. Problems: 

XVII. Measures: 

XVIII, XIX. Measures: 

XX. Problems: 

XXI. Measures : 

XXII. Measures : 

XXIII. Measures : 

XXIV. Problems: 
XXV. Problems: 

XXVI. Problems: 



PAGE 

By Halves and Thirds to 10 90 

Length 90 

At the Dry-Goods Store 91 

By Fourths and Fifths to 10 92 

Areas 92 

At a Hardware Store 93 

Solids 94 

Liquids 94 

Dry Substances 94 

At the Provision Store 96 

Weight 96 

Time 96 

At the Balieshop 97 

Counting 98 

Paper 98 

United States Money 98 

At the Stationery Store 99 

Miscellaneous 100 

Miscellaneous 101 



GRADE IV. FOURTH SERIES 



I. Two-Process Examples : Addition and Subtraction . . . 102 

II, III. Addition : Four One-Figure Numbers 102 

IV. Problems of the Conductor 103 

V. Two-Process Examples : Addition and Subtraction . . . 104 

VI, VII. Addition : Five One-Figure Numbers 104 

VIII. Problems of the Post Office 105 

IX. Two-Process Examples : + , — , and -=- 106 

X, XI. Making Change : To |100 106 

XII. Problems of the Fruit Seller 107 

XIII. Two-Process Examples : +, — , x,and-=- 108 

XIV, XV. Multiplication : United States Money 108 

XVI. Problems of the Dairy 109 

XVII. Fractional Parts : With Remainders 110 

XVIII, XIX. Division : With Remainders 110 

XX. Problems of the Carpenter Ill 

XXI. Fractional Parts : With Remainders 112 

XXII, XXIII. Division : With Remainders 112 

XXIV. Problems of the Farmer 113 

XXV. Problems: Miscellaneous 114 

XXVI. Problems : Miscellaneous 116 

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SUGGESTIONS TO TEACHERS 

MENTAL AND WRITTEN AKITHMETIC 

The term mental is not a very happy one when used to dis- 
tinguish so-called mental arithmetic from written arithmetic. 
Of course all arithmetic is in its origin mental. Writing has 
no place in arithmetic except as a means of recording the results 
of thinking and as a mechanical help to thinking when the com- 
putations are too complex for the mind to perform unaided. 

Mental arithmetic and oral arithmetic are terms that are often 
used synonymously to designate that kind of arithmetical work 
that is done without the help of pencil, pen, or crayon. It is in 
this sense that mental is used in this book. All the exercises, 
abstract and concrete, are to be done without the pencil. 

There are two considerations relating to written arithmetic 
that deserve the teacher's serious attention. 

The first consideration is this: While writing is in theory 
merely a mechanical aid to mental arithmetic, as a matter of 
fact the act of writing does introduce new factors into the 
mental processes. It seems to influence the mind to use long, 
cumbersome, uneconomical ways of calculating, instead of the 
short, economical ways employed in purely mental calculation. 
This influence has been overlooked by teachers in the past; 
it has even been strengthened too often by an insistence upon 
long and elaborate "figuring" in all written work, although the 
same examples when done mentally have been calculated in 
simple, direct ways. 



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xii PEACTICE EXERCISES IN MENTAL ARITHMETIC 

This common practice is wrong and retards the development 
of both accuracy and speed. Pupils should be trained to do all 
written work, whenever it is possible, by the same methods of 
thinking that they use in mental work. 

The second consideration to be taken account of in written 
arithmetic is this : In a comparison of the relative value of oral 
arithmetic and written arithmetic it should be recognized that 
the oral form of expression is a means of training ; it is not an 
end in itself. While mental activity is fundamental to both 
oral and written expression, it is the written form that is by 
far the more used, and it is the form by which alone mathe- 
matical progress may be made into advanced fields. 

Therefore, while the oral expression is insisted on for the exer- 
cises in this book, it is not for oral expression's sake ; the exer- 
cises are devised to train pupils to use the fundamentals in 
arithmetic so skillfully that their written work may be done 
more easily and correctly. This oral efl&ciency should be "car- 
ried over" into written work, a teaching task whose difficulty is 
not generally recognized. 

THE PURPOSE OF THIS BOOK 

From the foregoing it will be seen that this book is not 
intended to replace the regular textbook. It has a dijBferent 
purpose. It is a supplement to it. In the regular textbook 
the oral exercises are principally to give practice in the new 
subject that has been taught. In this book all the exercises 
are to give practice in what should be abeady famiUar, with 
a view to developing mastery, skill, and facility. 

For instance, the first exercises in this book involve combi- 
nations that were learned doubtless in the first grade. From 
the Contents it will be seen that the work throughout is review 



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SUGGESTIONS TO TEACHEES xiii 

so far as the number combinations are concerned. The methods 
of calculation and of drill are new, and these should lead to 
the laying of a solid arithmetical foundation. 

From the foregoing it follows that this book, although used 
quite independently of the regular textbook, will greatly enhance 
the results from the use of the latter book. 

THE ABSTRACT EXERCISES 

The abstract exercises provide training in purely mental 
computations to the end that each pupil may acquire a reason- 
able degree of accuracy and speed (that is, proportioned to his 
native ability) in the arithmetic of his daily needs and in the 
arithmetic that is necessaiy to progress in mathematical study. 

STANDARDS OF ACCURACY AND SPEED 

If one should ask, "How accurate and how speedy should 
this mastery be ? " the answer must be indefinite. The human 
brain is not an absolutely accurate machine, and its memory- 
is not perfect. The action of the mind is much affected by 
weather, condition of health, either temporary or permanent, 
and by immediate social or other surroundings. Moreover, as 
noted previously, minds differ one from the other in their 
ability to attain accuracy and speed and in memory. There is, 
there can be, therefore, no absolute standard of mathematical 
attainments to which all pupils should be forced. 

Professor Thomdike has said on this point that for the simple 
combinations in all the processes (that is, 6 + 7, 13 — 7, 9x3, 
72 -*- 8), if a child can give his answers in three seconds there 
is absolute control over the process, and the process can be 
considered as under reflex controL 



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xiv PRACTICE EXERCISES IN MENTAL ARITHMETIC 

It has been clearly proved, not alone in reading but in arith- 
metic, that slowness does not contribute to accuracy, but rather 
retards its development. The effort to accelerate seems to inten- 
sify attention. Perhaps a good general standard of speed is that 
of good oral reading, allowing for individual differences of tem- 
perament. In good oral reading, hurrying is avoided but a ready 
and intelligent rendering of the text without hesitation Is desired. 

In fact, these arithmetical combinations may be thought of as 
constituting an arithmetical vocabulary. It is as desirable, even 
as necessary, that pupils know the essential vocabulary in the 
one subject as that they know it in the other, and to the same 
degree of mastery. 

USING THE ABSTRACT EXERCISES 

1. It is a principle pretty well established in all lines of 
human activity that short periods of intensive practice are 
better in' developing skill than long periods. It is impossible 
to make a hard-and-fast rule regulating the length of the 
period, but it should be long enough to allow each pupil to 
get some training. It therefore follows that the class should be 
small, not over twenty pupils. If a class is larger than this it 
should be divided into two groups for mental-arithmetic work. 
In a small class a good deal can be accomplished in ten minutes. 

2. Show the pupils what you want them to do and how you 
want them to do it by going through the exercise for them. 

In this showing-exercise use the speed that you wish the 
pupils to use and give only the answers as they should be 
given by the pupils ; that is, they should not say " 7 and 8 
are 15," but looking at the combination they should say " 15," 
as they read a word without spelling it. 

Show the pupils in this way with each new exercise. 

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SUGGESTIONS TO TEACHERS xv 

3. While one pupil is reciting, all the others in the class should 
follow closely, watching for errors. If it is necessary to maintain 
attention, call on them out of turn to " go on from there." 

4. Let each exercise be repeated until the majority of the 
class know and meet your standard. 

5. From time to time have each pupil note on a piece of 
paper the combinations on which he hesitates. These are for 
private study. j 

6. Subordinate speed to accuracy, but do not forget nor 
neglect speed. 

7. Practice should be varied by proceeding with the exercises 
from right to left, and up and down in columns. 

8. The pencil should not be used in these exercises except 
as suggested in paragraph 5. 

9. The suggestions for methods of thinking in connection with 
the exercises should be faithfully followed and applied also in 
all written work. 

THE CONCRETE-PROBLEM EXERCISES 

The problems in each quarter of the grade work deal with 
one familiar situation. In the first quarter of the third grade 
they relate to the home, in the second quarter to play, etc. 
This plan has been adopted so that pupils may think consecu- 
tively in one field of arithmetical application at a time. It is 
believed that this both simplifies and intensifies the thinking 
and prepares the pupils to study more intelligently the real sit- 
uations about them when they are assigned the task of making 
original problems. 

It will be noted also that the problems on each page involve 
the number combinations and the processes that have been 
studied on the opposite page of abstract exercises. The problems 

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xvi PRACTICE EXERCISES IN MENTAL ARITHMETIC 

have been constructed to the end that pupils may become familiar 
with the dijBferent varieties of statement of problems in addition, 
subtraction, multiplication, and division. 

These problems are not as difficult as most children of these 
grades can do. They are not standards of difficulty. On the 
contrary, like the abstract exercises, they are exercises to give 
facility and skill in interpreting problems. Therefore, language 
and number difficulties have been removed, and one process is 
dealt with in each exercise but set in a variety of simple lan- 
guage forms. 

Two pages of miscellaneous problems are put at the end of 
each quarter s work to give further and more varied problem 
training. 

MAKING ORIGINAL PROBLEMS 

At the bottom of each page of problems is a suggestion that 
pupils make and bring to the class problems similar to those 
they have just solved. These problems should not be imaginary 
but real problems that they . themselves discover in situations 
similar to those they have just solved on the same page. 

There are two reasons for studying real situations in this way. 

In the first place, if pupils have had no actual experience with 
the material described or dealt with in a problem, or in the 
situation in which the problem is set, that problem is as abstract 
as if the words were not used, but the figures only. You may 
test this for yourself by attempting to solve problems in navi- 
gation, astronomy, or any other field in which you are not 
familiar. Your trouble and confusion will be caused by your in- 
ability to picture the problem, and that inability will persist until 
you have had a concrete (that is, a real, first-hand, conscious) 
contact with the situation. 

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SUGGESTIONS TO TEACHEKS xvii 

In the second place, that contact must be a conscious one. It 
is one of the lessons that we teachers have been slow to leam ; 
namely, that mere personal contact does not give us a knowledge 
of things. Our eyes do not see, our ears do not hear, our mind 
does not think about things until it begins to study them with 
a purpose. Children go year after year to the post office without 
being conscious of the peculiar nature of the post office. Country 
children live in the . midst of nature without seeing nature. 
City children Hve under the shadow of tall skyscrapers with- 
out realizing what casts the shadow. 

So the making of original problems, if the data for them are 
those actually discovered in a purposeful study of real situa- 
tions, will open the minds of the pupils to their surroundings 
and will give them training in stating the problems they find 
there. Both of these values are fundamental in developing skill 
in solving problems. 

THE USE OF THE PKOBLEM EXERCISES 

1. Let the entire page of problems be assigned to the class 
for silent reading. 

2. The first lesson in class may be an oral reading and 
discussion lesson without reference to problem solving. The 
purpose is to understand the meaning of the problems and 
to exchange experiences relating to other similar situations. 
The character of the problems will lead to this discussion, it 
is hoped. 

3. Now take the problems one by one. Each may be read 
again, orally or silently, as the teacher decides. The purpose now 
is to have the pupil see clearly and state (a) what is to be done 
and (J) the answer. 

Of course the pencil will not be used. 



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xviii PRACTICE EXERCISES IN MENTAL ARITHMETIC 

4. If the pupil makes a mistake in (a) or in (6) do not resort to 
explanations and questions ; allow him to sit down and think it 
out by himself while the class proceeds with the next problem. 

Note. Pupils think logically. Their minds are so made that logical 
thinking is their natural way of thinking. But the ability to state reasons, 
to give and understand "explanations," — that is, the if*s, ancTs, thens, 
therefore' s, because' s, — develops after childhood has passed. 

To put the matter in another way, the mind tends to act correctly in 
determining the process that should be applied- in a given problem once 
the problem situation is understood. There need be, then, but an abundance 
of practice in dealing with word problems involving familiar situations to 
produce quickness and accuracy in this mental reaction. 

5. Encourage and reward the use in written problems of 
methods of solution and of computation employed in mental 
exercises. 

MATHEMATICAL JUDGMENT 

Those who use numbers skillfully are constantly employing 
what may be called a calculation or a computation judgment. 
One out of many possible cases will illustrate this. 

Problem. At $0.12^ each, what do 10 handkerchiefs cost ? 

There is no doubt here about the process to be used. 

$0.12J is to be multiplied by 10. But there are at least three 

possible ways of making the calculation. 

(1) $0.12^ (2) $0.12i = $0,125 (3) $0.12^ 

^Q $0,125 X 10 = $1.25 $0.25 x 5 = $1.25 

5 
^ ork (Multiplication by moving (Multiplying by the 

.. decimal point.) factors of 10.) 

$l.^o 

This, it is evident, is a matter of calculation judgment The 
question is which of three possible ways of multiplying is best 
in this particular case. 



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SUGGESTIONS TO TEACHEES xix 

To answer the question the pupil must have facility in using 
the different methods and readiness in applying each according 
to the conditions in given cases. This readiness and facility 
can come only with practice, and this practice should begin 
early. It is provided for in this book. 

There is another need for judgment in determining the best 
process to apply in a given case. To illustrate : 

Problem. If one handkerchief costs $0.12]^, how many can be 
bought for $1.50 ? 

Here there is a question of what process rather than of how 
to carry out the process. It is a question of how to solve the 
problem rather than of how to compute. 

This problem may be solved by division, or by division and 
addition. 

(1) 11.50 H- $0.12^ = (2) $0.12^ = $f 

♦0.125) $1.50 Then 8 handkerchiefs may be 

(or) bought for $1.00, and 4 handker- 

41 Kf) ^ = chiefs for $0.50. Therefore 12 may 

* ^ $0.25 "" be bought for $1.50. 

As in the case of calculation judgment this process or problem 
judgment develops with a knowledge of alternative methods of 
solution and with practice in applying different methods to the 
same problems until the judgments are made easily and quickly. 

Training to this end should not be delayed too long, for 
clumsy and troublesome habits of work will become fixed, as 
they are fixed in the minds of so many school children to-day. 

A beginning of training in this kind of judgment is made in 
connection with many problems in this book. 

•There is a third kind of mathematical judgment that chil- 
dren should be trained to use. It is involved in answering the 

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XX PRACTICE EXERCISES IN MENTAL ARITHMETIC 

question, " Is my answer reasonable ? " If the minds of pupils 
are properly alert they will frequently ask: "Is this problem 
reasonable ? Are the prices and quantities stated in the prob- 
lem such as are likely to occur in real problems ? " 

Incentives to exercise this kind of judgment are scattered 
through this book, and it is hoped that teachers will make use 
of them. Additional opportunities for judging the reasonableness 
of the problems and of problem answers are given in the original 
problems that the children themselves make and bring to class. 



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PRACTICE EXERCISES IN 
MENTAL ARITHMETIC 



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GRADE III. FIRST SERIES 

Note. Pupils should be trained to state the sums at the same rate of 
speed as they read familiar text. See Suggestions to Teachers. 









I. > 


A^DDITIOm 


1 








A. 2 


1 


1 


1 


1 


6 


1 


4 


1 


1 


3 


9 


7 


1 


1 


5 


1 


8 


B. 2 


2 


5 


2 


2 


2 


8 


2 


3 


2 


6 


2 


7 


9 


3 


2 


4 


3 








II. 


ADDITION 








A. 5 


3 


4 


3 


6 


3 


4 


4 


7 


3 


7 


3 


8 


3 


9 


4 


9 


4 


B. 4 


8 


4 


7 


5 


5 


9 


5 


6 


5 


4 


6 


5 


5 


6 


5 


8 


6 








III. 


ADDITION 








A. 9 


6 


8 


7 


9 


7 


8 


9 


9 


6 


7 


6 


7 


7 


8 


8 


8 


9 


B. 1 





2 





3 





5 





9 





1 





2 





4 





6 





C. 8 


6 


7 


8 


6 


8 


5 


9 


7 


9 


8 


9 


5 


9 


7 


7 


4 


6 


D. 5 


4 


9 


8 


8 


4 


7 


6 . 


6 


9 


7 


3 


3 


8 


8 


3 


4 


5 














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GRADE III. FIRST SERIES 3 

IV. PROBLEMS; AT HOME 

1. In John's family there are 4 people. One day 3 
friends come to dinner. How many plates should mother 
put on the table that day for dinner? 

2. Usually John takes 5 minutes to get ready for 
dinner, but he spends 2 minutes more the day the visitors 
come. How long does he take that day ? 

3. It is a part of Susan's work at home to sweep the 
front and back steps each day. There are 6 front steps 
and 5 back steps. How many steps does she sweep? 

4. How many stockings will mother mend if she finds 
that John has 3 stockings with holes in them and Susan 
has 3 stockings with holes in them? 

5. There are 7 rugs on the floors upstairs and 8 rugs 
on the lower floor in John's home. If he cleaned them 
all, how many would be clean? 

6. Susan's father decides to buy new curtains for the 
kitchen and for the dining room. How many ciu'tains 
will be required for the 5 windows of the kitchen and 
the 3 windows of the dining room ? 

7. If John has 8 books in his library and Susan has 
9 books in her library, how many books do they have 
together ? 

8. How many rolls does mother make when she bakes 
9 in one pan and 6 in another pan? 

Additional Work. Each pupil should write out and bring to class 
a similar problem of his own. 

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4 PEACTICE EXERCISES IN MENTAL ARITHMETIC 

Note. Train pupils to recognize the total sums at a glance, that is, 
12 + 6 = 18 ; no/ 2 + 6= 8, and 1 ten = 18. These are really a review of 
Exercises I-III. 









V. ADDITION 








A. 1 


2 


1 


11 3 12 


7 


3 


12 


10 


10 


11 


2 16 4 


10 


12 


5 



5 


17 


15 


15 


14 


12 


12 


13 


3 


13 


_2 


3 


5 


_4 


2 


_6 


_3 


14 









VI. ADDITION 








A. 15 


11 


12 


5 6 2 


3 


16 


13 


4 


9 


7 


14 14 15 


17 


2 


2 



B. 16 


13 





9 


11 


14 


1 


13 


14 


_0 


4 


19 


10 


4 


2 


19 


7 





a 16 


13 


14 


16 


2 


14 


13 


2 


15 


4 


_5 


5 


3 


13 


3 


6 


14 


J 



VII. ADDITION 
^.10 + 10= 4 + 15= 18 + 2= 4 + 13 = 

5. 12 + 8= 13 + 5= 15 + 5= 4 + 16 = 

C. 12 + 1= 18 + 0= 13 + 6= 18 + 2 = 

D. + 20= 13 + 4= 2 + 17= 16 + 3 = 

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GEADE ni. FIEST SERIES 5 

VIII. PROBLEMS: AT HOME 

1. Samuel fills his mother's wood box every morning. 
One morning he filled it by carrying 9 sticks at one trip 
from the woodshed and 11 sticks at another trip. How 
many sticks filled the box? 

2. How many minutes does Mary work when she helps 
her mother for 10 minutes washing the dinner dishes and 
5 minutes setting the table ? 

3. If Samuel has 6 cents of his own in his pocket and 
his mother gives him 12 cents with which to do an errand, 
how much money does he carry to the store ? 

4. Mary is asked to dust all the chairs in the living room 
and dining room. There are 3 rockers and 11 other chairs. 
How many chairs are there to be dusted ? 

5. One day Mary puts her mother's workbasket in order. 
Sbe finds 12 spools of white thread and 5 spools of colored 
thread. How many spools are in the basket ? 

6. If 5 one day after school out in the orchard, Sam picks 
up 8 quarts of pears and Mary picks up 12 quarts, how 
many quarts of pears do both children pick up? 

7. When mother has put up 13 jars of peach preserves 
and 6 jars of cherry preserves, how many jars will she 
have for winter? 

Additional Work. Each pupil should write out and bring to class 
a similar problem of his oum. 

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6 PRACTICE EXERCISES IN MENTAL ARITHMETIC 

Note. Pupils should state the answers without repeating the numbers 
that are to be subtracted. See Suggestions to Teachers. 

IX. SUBTRACTION 



A. 2 


3 


9 


7 


1 


1 


6 


5 


4 


1 


1 


1 


1 


1 





1 


1 


1 


B. 2 


6 


2 


7 


9 


5 


8 


4 • 


3 


2 


2 





2 


2 


2 


2 


2 


2 



X. SUBTRACTION 



^. 3 
3 


5 
3 


7 
3 


4 
3 


8 
3 


6 
3 


9 
3 


10 
4 


4 



B 5 
5 


9 
4 


7 
4 


5 
4 


8 
4 


10 

2 


10 
6 


6 
4 


7 
5 



XL SUBTRACTION 



A. 6 


9 


8 


6 


9 


7 


8 7 7 


5 


5 


5 


6 


6 


6 


6 7 


B. 9 


8 


10 


9 


9 


10 


10 10 .10 


7 


7 


8 


8 


9 


5 


3 7 10 


a 8 


7 


6 


3 


4 


5 


6 5 7 











3 


4 


5 


2 3 4 


D. 9 


6 


5 


7 


8 


9 


7 9 9 


5 


4 


2 


3 


5 


4 


5 7 2 

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GRADE III. FIRST SERIES 7 

XII. PROBLEMS: AT HOME 

1. Mother finds that she has 9 eggs. She uses 2 eggs 
in a cake. How many are left? 

2. Hannah is sent to the store to buy a yeast cake. 
She is given 5 cents, and the yeast cake costs 2 cents. 
What change should she bring back? 

3. If Hannah sets the supper table for 7 people and 
only 5 people come to supper, how many empty places 
are there? 

4. Harry can walk to the store from his home in 
8 minutes, but when his mother wants an errand done in a 
hurry, he can run there in 5 minutes. How many minutes 
does he save by running ? 

5. How much taller is Harry's father, who is 6 feet tall, 
than Harry, who is 3 feet tall ? 

6. There are 10 napkins to be laundered. When mother 
has laundered 3 of them, how many remain to be done ? 

7. Mother asks Hannah to pour 3 pints of milk into a 
bowl that will hold 8 pints. How many more pints will it 
take to fill it after Hannah has poured in her milk ? 

8. In the dining room there are 6 chairs. The family 
uses only 4 of them at breakfast time. How many chairs 
are unused at breakfast ? 

9. How many handkerchiefs has Harry after he has 
lost 2 from the 9 that he had after last Christmas? 

Additional Work. Each pupil should write out and bring to class 
a similar problem of his own. 

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8 PEACTICE EXERCISES IN MENTAL ARITHMETIC 

Note. The exercises on this page give training in recognizing differences 
within the limits 11-10 in the minuend and 0-10 in the subtrahend. 



XIII. SUBTRACTION 

A. 11 11 12 11 12 11 12 14 11 

B. 11 12 15 11 11 12 11 12 13 

XIV. SUBTRACTION 

A. 14 14 13 12 14 14 13 13 14 
455769647 



B. 13 


14 


15 


14 


13 


14 


15 


13 


15 


7 


_9 


_7_ 


_]_ 


9 


_8 


_9 


8 


_6 


C. 16 


17 


18 


19 


19 


17 


19 


15 


15 


_2 


5 


2 


7 


3 


2 


4 


3 


2 



XV. SUBTRACTION 
^.15-8= 16-7= 17-8= 18-10 = 

i?. 16-9= 13-0= 18-3= 16-8 = 

C 18-4= 17-3= 18-9= 19-6 = 

D. 17-4= 19-2= 18-4= 19-5 = 

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GEADE III. FIRST SERIES 9 

XVI. PROBLEMS: AT HOME 

1. There are 14 days in 2 weeks. Of these 14 days 
children go to school 10 days. How many days in 
2 weeks do children have no school? 

2. Sarah invited 10 friends to her doll's party, but 4 
of them could not come. How many came? 

3. For the party Sarah counted out 18 lumps of sugar. 
Of these one dozen lumps were eaten. How many lumps 
were left? 

4. What is the difference between Frank's age and 
Sarah's age if Frank is 9 years old and Sarah is 16 
years old? 

5. Sarah has 19 cents in her bank. She takes out the 
19 cents to spend for a birthday present for her mother. 
How much is left in the bank ? 

. 6. It is Frank's work to keep the front walk clean. 
The walk is 18 feet long. After he has swept 12 feet 
of it, how many feet remain to be swept? 

7. Mother buys 16 quarts of apples. She uses some 
for cooking and she gives some to the children. There 
are 7 quarts left. How many quarts were used ? 

8. The children have a party for which mother makes 
17 pop-corn balls. After the party there are 5 pop^jom 
balls left. How many were eaten? 

Additional Work, Each pupil should write out and bring to class 
a similar problem of his own. 

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10 PRACTICE EXERCISES IN MENTAL ARITHMETIC 

Note. Pupils should be trained to recognize (without conscious calcu- 
lation) these products. They should become familiar with the fact that 
the product is the same whichever term is used as multiplier. For addi- 
tional practice these exercises may be copied or written on the board, 
reversing the terms. 

XVII. MULTIPLICATION 



A. 1 
1 


2 
1 


3 
1 


2 
2 


3 

2 


10 

_2 


6 

2 


4 
2 


3 
3 


B. 5 

2 


8 
2 


9 
3 


4 
3 


7 
2 


5 
3 


9 
2 


7 
3 


10 
1 



XVIII. MULTIPLICATION 



A. 4 
4 


6 
3 


5 

4 


8 
3 


9 

4 


5 
5 


6 
4 


9 

5 


7 
4 


B. 6 
5 


8 
4 


7 
5 


6 
6 


8 
5 


9 
6 


7 
6 


7 
7 


8 
6 



XIX. MULTIPLICATION 
A 7x8= 10x10= 9x9= 8x8 = 

5. 2x10= 8x9= 1x7= 7x9 = 

C. 5x1= 1x5= 5x10= 10x5 = 

i). 3 x 10 = 4 X 10 = 9 X 10 = 10 X 8 = 

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GRADE III. FIRST SERIES 11 

XX. PROBLEMS: AT HOME 

1. Peter saves 3 cents a week for 7 weeks. How much 
mone;^ does he then have ? 

2. How many doll's dresses has Frances if she has 4 
dolls and each doll has 4 dresses? 

3. In the doll house there are 3 rooms. In each room 
there are 2 chairs. How many chairs are there in the 
doll house? 

4. How much money should Frances take with her to 
the store when she goes to buy 6 buns at 2 cents each? 

5. Mother has made 2 pats of butter to show you how 
to make them. She asks you to make 9 times as many. 
How many will you make ? 

6. Peter has a garden. He gives mother 1 bunch of 
radishes from it each day for a week. How many bunches 
does he give her ? 

7. If there are 5 people in a family and each one eats 
3 rolls for breakfast, how many rolls must be baked for 
breakfast ? 

8. Frances wants to make a string of beads for each 
of her 4 dolls. She finds that 10 beads will make a very 
good string. How many beads does she need? 

9. There are 8 chairs in the dining room. Each chair 
has 4 legs. How many legs have all the chairs together ? 

Additional Work. Each pupil should write out and bring to class 
a similar problem of his otvn. 

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12 PRACTICE EXERCISES IN MENTAL ARITHMETIC 

Note. Quotients should be recognized without conscious calculation, 
as in previous exercises. The teacher will note that in the following 
exercises the dividends are the products in the preceding multiplication 
exercises. For additional practice the dividends may be copied on the 
board, using for divisors the quotients in the following exercises. 







XXI. DIVISION 






A. 1)1 


1)2 


1)3 


2)4 


2)6 


2)20 


B. 2)12 


2)8 


3)9 


2)10 


2)16 


3)27 


a 3)12 


2)14 


3)15 


2)18 


3)21 


1)10 






XXII. DIVISION 







A. 4)IQ 3JIS 4)20 3)24 4)36 5)25 

B. 4)24 5)45 4)28 5)30 4)32 5)36 
a 6)36 5)40 6)54 6)42 7)49 6)48 

XXIII. DIVISION 
A. 56-1-7= 100-!- 10 = 

5. 20-!- 2= 72-»-8 = 

C. 5h-5= 5-i-l = 

D. 30-^3= 40-»-4 = 



81-!- 9 = 


64-!- 8 = 


7-»-l = 


63-^7 = 


50-!- 5 = 


50-h10 = 


90-^9 = 


80-^8 = 


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GKADE III. FIRST SERIES 13 

XXIV. PROBLEMS: AT HOME 

1. Mother wants to divide 9 pieces of candy among 
her 3 children. How many pieces shall she give to each 
child? 

2. Harry has in his garden a row of peas 18 feet long. 
He plans to weed it during the next 6 days. How many 
feet should he weed each day ? 

3. There are 14 children at play. They counted off 
into 2 equal groups. How many children were in each 
group? 

4. If the 14 children had counted off into 7 equal 
groups, how many would have been in each group? 

5. Harold and Barbara had 2 children come to play' 
with them. Mother gave them a dozen apples. If the 
apples were divided equally among the children, how 
many would each have? 

6. The children were helping mother make sandwiches 
for a picnic. After a while she counted and said : *' There 
are 20 sandwiches, and there will be 5 people. I wonder 
if it is enough." How many could each person have? 
(Do you think that would be enough?) 

7. Mother's biscuit pan holds 18 biscuits. There are 
3 long rows of biscuits in the pan. How many in each 
long row? 

Additional Work. Each pupil should write out and bring to class 
a similar problem of his own. 

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14 PRACTICE EXERCISES IN MENTAL ARITHMETIC 
XXV. PROBLEMS: MISCELLANEOUS 

Note. This lesson introduces what may be called the "completion type " 
of problem. The correct number should be read at the dash. 

1. Mother said to Rebecca: *' There are 7 in our family 
and we shall have 12 guests on Thanksgiving Day. If 
they all come we must set the table for people." 

2. Father said: "For our own family a 6-pound turkey 
would be big enough, but if the other 12 people come we 

shall need a turkey 3 times as big. That will be an 

pound turkey." 

3. For the Thanksgiving dinner mother baked 4 loaves 
of bread. She said, "If I cut each loaf into 10 slices, I 

shall have slices of bread." (Do you think that 

would be enough?) 

4. Rebecca promised to make a place card for each 
of the 19 people that were expected at the Thanksgiving 
dinner. The day before Thanksgiving she found she had 
made only 9 of them. So she set to work to make the 
other cards. 

5. Of the 19 people expected at dinner 2 sent word 

that they could not come. So the table was set for 

people. 

6. To decorate the table father brought home the day 
before Thanksgiving 6 red roses and 9 white roses. This 
made flowers for the table. 

Additional Work. Each pupil should write out and bring to class 
a similar problem of his own. 

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GRADE III. FIRST SERIES 15 

XXVI. PROBLEMS: MISCELLANEOUS 

1. Tom and Sam are building a playhouse of some 
bricks. Tom says, " I can carry 5 bricks at once." Sam 
says, '* I can carry 3 more than that." How many can 
Sam carry? 

2. Sarah picked 13 roses from a rosebush. She gave 
7 of them to her mother. How many did she keep 
for herself? 

3. If Sarah wanted to make 12 Christmas presents 
and finished 7 of them in November, how many were 
left to be made in December? 

4. One week in the fall Tom spent 1 hour each day 
for 6 days raking up the leaves around the house. On 

counting it up he found that he had worked hours 

raking leaves. 

5. Sarah spent 15 minutes sewing buttons on her doll's 
dress. In that time she sewed on 3 buttons. About how 
long did it take her to sew on 1 button ? 

6. It is Tom's work to keep his mother supplied with 
kindling wood. His father buys wood in sticks 4 feet 
long. If Tom saws these sticks into 4 pieces each, how 
long is each piece? 

7. Tom finds that when he has sawed 5 sticks into 
4 pieces each he has pieces. 

8. Mother asks Sarah to find how many handkerchiefs 
she and Tom have. She finds 8 of Tom's and 7 of her own 
and reports that together they have handkerchiefs. 

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GRADE III. SECOND SERIES 

Note. Practice is here given in "addition by endings"; that is, in not- 
ing that the sum of two units is the same irrespective of the tens with which 
they may stand. Other combinations may be made for further practice on 
the board. 

I. ADDITION 



A. 10 
1 


20 
1 


30 
J. 


42 
_1 


52 
1 


62 
1 


7 
2 


17 

2 


27 
_2 


B. 37 
2 


47 
2 


77 
2 


6 

2 


16 
2 


26 
2 


7 
3 


17 

3 


87 








II. ADDITION 








A. 5 
_3 


15 
3 


25 
3 


95 
3 


3 
3 


23 
3 


63 
3 


6 

_4 


26 
4 


B. 56 
_4 


5 
_4 


75 
4 


85 
4 


4 
5 


14 

5 


24 
_5 


3 

5 


43 
5 








III. ADDITION 








A. 73 
5 


3 

6 


53 
_6 


83 
_6 


2 
6 


12 
6 


22 
_6 


3 

7 


33 

7 


B. 43 

J_ 


10 

7 


20 

7 


30 

7 


11 

8 


21 

8 


31 

_8 


10 
_9 


20 
9 


C. 6 
3 


16 
13 


26 
23 


16 
53 


5 
14 


15 
34 


25 
64 


3 
1 


13 
11 


D, 23 
31 


13 

81 


6 

2 


26 
22 


36 

42 


6 
92 


15 
12 


15 

42 


25 
62 














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Google 



GRADE III. SECOND SERIES 17 

IV. PROBLEMS: AT PLAY 

1. At the beginning of the marble season Peter has 
22 marbles. He buys 10 more. How many does he have 
then? 

2. If Horace has 32 marbles and buys 10 more, how 
many does he have? 

3. Ruth makes Peter a bag for his marbles. He puts 
55 marbles in the bag. How many are in the bag after 
he has put in 4 more? 

4. If Peter had put in the bag 35 marbles first and 
then 4, he would have had marbles in the bag. 

5. How much money did Horace spend for marbles if 
he spent 12 cents that his father gave him and 8 cents 
that he earned? 

6. Theodore spends 22 cents one day for marbles 

and 8 cents the next. On both days he spends 

cents. 

7. Ruth likes to play marbles also. She buys 17 marbles 
and Peter gives her 2. She then has marbles. 

8. If Horace gives her 2 marbles one day when she has 
37, how many marbles does she have? 

9. When the end of the marble season comes Peter 
counts his marbles and finds that he has 3 green and 13 
yellow ones, or in all. 

Additional Work. Each pupil should tmrite out and bring to class 
a similar problem of his oum. 

Digitized byCjOOQlC 



18 PRACTICE EXERCISES IN MENTAL ARITHMETIC 

Note. The following are review exercises of the more troublesome 
combinations. Pupils should practice until they recognize these sums 
as readily as the easier ones, for on this readiness depends success in 
succeeding exercises. 











V. ADDITION 










A. 


6 


6 


9 


7 


6 


4 


7 


8 


6 




2 


6 


4 


9 


8 


6 


6 


3 


9 


B. 


3 


8 


9 


5 


3 


6 


9 


5 


7 




4 


5 


9 


9 


2 


5 


2 


7 


2 










VI. ADDITION 








A. 


4 


5 


" 4 


6 


1 


8 


9 


8 


7 




8 


4 


7 


3 


7 


7 


3 


9 


3 


B. 


3 


8 


16 


13 


5 


2 


2 


12 


13 




5 


8 


3 


6 


12 


15 


17 


Jl 


_5 


C. 


4 


13 


5 


4 


19 


7 


5 


9 


18 




15 


4 


14 


13 


_8 


18 


17 


16 


5 



VII. ADDITION 
A 16 + 4= 14 + 6= 15 + 3= 17 + 2 = 

A 3 + 17= 13 + 7= 17 + 7= 6 + 16 = 

C. 4 + 15= 16 + 3= 2 + 16= 14 + 3 = 

D. 18 + 6= 4 + 19= 7 + 16= 5 + 19 = 

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GRADE III. SECOND SERIES 19 

VIII. PROBLEMS: AT PLAY 

1. Edith and Amy are jumping rope. Edith jumps 9 
times and Amy jumps 4 times. They together jump 

times. 

2. How many jumps does Edith make in two trials if 
on the first trial she jumps 8 times and on the second 
trial 3 times? 

3. The two girls have jump ropes of different lengths. 
One is 5 feet long, the other 6 feet. If they were put end 
to end, how long a rope would they make ? 

4. Peter and Edith are playing jackstraws. After a 
time Peter counts his pile and finds he has 12 straws. 
Edith has 8 straws in her pile. How many straws have 
they both drawn ? 

5. Amy joins the game of jackstraws. If she draws 
out 7 straws and afterwards 11 more, how many should 
there be in her pile ? 

6. Peter and Will decide to put their money together 
to buy a baseball. Peter has 4 cents and Will succeeds in 
finding 6 cents. How much do they both have ? (Is this 
enough to buy a ball ?) 

7. Some boys^are getting ready for a snowball fight. 
They make 39 balls to use when they are attacked and 
8 to throw at once. They then must have 'made in all 

balls. 

Additional Work. Each pupil Bhovld write out and bring to class 
a similar problem of his own. 

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20 PRACTICE EXERCISES IN MENTAL ARITHMETIC 

Note. The following are exercises in "subtraction by endings "; minu- 
ends not exceeding 100, subtrahends not exceeding 9. Exercises do not 
involve "borrowing." 

IX. SUBTRACTION 

A. 11 21 31 41 14 24 34 64 94 
J.J.J.J._2_2_2_2^ 

B. 13 33 53 45 85 76 26 86 16 

33.3 1 12 2 2 3 



X. SUBTRACTION 

A. 47 27 97 18 38 68 19 49 89 
444555666 



B. 39 


59 


19 


27 


57 


87 


28 


58 


18 


4 


_4 


_4 


5 


_5 


5 


_6 


_6 


6 


C. 98 


78 


48 


29 


19 


69 


55 


15 


25 


_3 


3 


_3 


5 


_5 


5 


2 


2 


_2 



XI. SUBTRACTION 

^.19-7= 59-7= 99-7= 29-7 = 

B. 19-S= 49 - 8 = 69 - 8 = * 19 - 8 = 

a 29-9=' 89-9= 17-3= 27-3 = 

i). 37 - 3 = 17 - 2 = 27 - 2 = 57 - 2 = 

.e:. 16-4= 36-4= 19-3= 49-3 = 



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GRADE III. SECOND SERIES 21 

XII. PROBLEMS: AT PLAY 

1. The children are playing store. Richard has in 
his store 14 nails, 24 toothpicks, and 54 pins. If he 
sells 3 of each of these, how many of each has he left? 

2. Marion makes for her store 5 mud pies, 15 loaves of 
bread, 35 rolls, and 25 cakes. She sells 4 of each of them 

and has left pies, loaves of bread, rolls, 

and cakes. 

3. Richard puts some buttons that his mother has 
given him in 4 piles according to size. In the first pile 
are 9 buttons, in the second 29 buttons, in the third 
69 buttons, and in the fourth 49 buttons. How many 
are left in each pile if he sells 7 buttons from each? 

4. Sarah makes 23 glasses of lemonade in one pail and 
13 glasses of orangeade in another pail. After she has 

sold 2 glasses from each pail she has left glasses of 

lemonade and glasses of orangeade. 

5. Henry sells stationery in his store. He has 39 sheets 
of white paper and 59 sheets of yellow paper. Richard 
buys 6 sheets of each kind. How much of each kind 
does Henry have left? 

6. Tom has in his store a pile of 88 beans, one of 
38 peas, and one of 68 kernels of com. Sarah buys 5 
from each pile. How much has Tom left in each pile? 

Additional Work. Each pupil should write out and bring to class 
a similar problem of his otm. 

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22 PRACTICE EXERCISES IN MENTAL ARITHMETIC 

Note. The following are review exercises of the more troublesome 
combinations of minuends to 20 and subtrahends to 10. Pupils should 
recognize them as readily as they do the easier ones. 



XIII. SUBTRACTION 



A. 5 
3 


9 
4 


8 
3 


7 
2 


10 

4 


7 
5 


7 
4 


9 

2 


7 
3 


B. 10 

2 


5 
2 


9 

7 


9 
5 


10 
6 


8 

2 


9 
3 


9 
6 


10 
3 



XIV. SUBTRACTION 



A. 10 


11 


13 


12 


11 


12 


11 


12 


13 


7 


2 


5 


4 


3 


_3 


4 


5 


4 


B. 13 


11 


14 


11 


12 


14 


11 


12 


14 


6 


_5 


_8 


_6 


7 


6 


7 


8 


_5 


a 10 


12 


14 


18 


19 


18 


17 


19 


17 


_5 


6 


_T_ 


_9 


_4 


3 


2 


2 


5 





XV. SUBTRACTION 

^.12-9= 11-8= 13-7= 11-9 = 

A 13-8= 15-6= 16-7= 17-8 = 

a 14-9= 13-9= 14-8= 15-7 = 

D. 17-9= 15-8= 16-9= 15-9 = 

JS-. 13-6= 11-5= 13-5= 12-4 = 



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GRADE III. SECOND SERIES 23 

XVI. PROBLEMS: AT PLAY 

1. In a potato race Luther misses 4 of the 12 potatoes 
in his row. How many does he pick up ? 

2. Susan picks up all of the 12 potatoes in her row, 
but 3 of them fall outside the box into which she should 

have dropped them. Therefore only potatoes are 

counted for her. 

3. If 5 rows of potatoes are laid out for the race, 

but only 3 children take part, there are rows too 

many. 

4. There are 18 grown people present to see the race. 
Of these 7 are men. How many women are there ? 

5. If there are 9 children present and only 3 of 

them take part in the race, there are children 

who watch. 

6. After the potato race how many grown people are 
left if 5 of them go home? 

7. A little later only 11 grown people are left; how 
many have then gone home? 

8. Of the 9 children only 7 are able to stay to a picnic 
dinner. Then children are obliged to leave. 

9. Four of the children at the dinner are boys. How 
many, then, are girls? 

Additional Work. Each pupil should write out and bring to class 
Q, similar problem of his own. 

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24 PRACTICE EXERCISES IN MENTAL ARITHMETIC 

Note. Exercises in recognizing (without conscious calculation) products 
not exceeding 100 : multiplicands of two figures, multipliers to 9. Pupils 
should recognize these products as readily as they do 2x3. These 
exercises may be put on the board with the order of the terms reversed. 



XVII. MULTIPLICATION 



A. 11 


12 


13 


14 


15 


20 


21 


22 


23 


_2 


_2 


_2 


_2 


2 


_2 


2 


_2 


2 


B. 24 


30 


31 


32 


33 


34 


40 


41 


42 


_2 


_2 


2 


2 


_2 


2 


2 


2 


2 



XVIII. MULTIPLICATION 



A. 43 


44 


11 


12 


13 


20 


22 


23 


30 


2 


2 


3 


3 


_3 


3 


3 


3 


J 


A 31 


32 


33 


11 


12 


20 


21 


22 


11 


_3 


3 


3 


4 


_4 


4 


4 


4 


5 



XIX. MULTIPLICATION 

^. 11 X 5 = 12 X 5 = 11 X 6 = 12 X 6 = 

A 11 X 7 = 12 X 7 = 11 X 8 = 12 X 8 = 

C. 11 X 9 = 25 X 2 = 25 X 3 = 25 x 4 = 

Z>. 50x1= 50x2= 35x2= 45x2 = 

^. 10 X 1 = 11 X 1 = 22 X 1 = 44 X 1 = 



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GRADE III. SECOND SERIES 25 

XX. PROBLEMS: AT PLAY 

1. Jerry can run around the house in 45 seconds, but it 
takes his little brother twice as long. The little brother 
runs around the house in seconds. 

2. How many marbles has James if he has 3 times as 
many as Warren, who has 20 marbles ? 

3. While little Ethel is making 15 mud pies, her older 
sister makes twice as many. How many does her sister 
make ? 

4. In Richard's play store 25 pebbles are called a 
bushel of potatoes. How many pebbles must he collect 
if he wants to have in his store 4 bushels of potatoes? 

5. John has 23 marbles and so has each of his two 
friends. How many marbles have they together? 

6. Ethel, Jane, and Rose are playing dominoes. Ethel 
counts 13 spots on the dominoes that she has left at 
the close of the game, and Jane counts 3 times as 
many on hers. How many does Jane count? Rose 
counts on her dominoes twice as many spots as Ethel 
does, or spots. 

7. Hannah wants to buy a set of doll's dishes, but it 
costs 3 times as much as she has, for she has only 25 cents. 
What is the price of the dishes ? 

Additional Work. Each pupil should write out and bring to class 
a similar problem of Ms otun. 

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26 PRACTICE EXERCISES IN MENTAL ARITHMETIC 

NuTE. Qaotients should be recognized without conscious calculation. 
Divisors to 9 ; dividends to 100. These exercises are the reverse of Exer- 
cises XVII-XIX. 



XXI. DIVISION 

A. 2)22 2)24 2)26 2)28 2)30 2)40 

B. 2)42 2)44 . 2)46 2)48 2)60 2)62 

C. 2)64 2)66 2)68 2)80 2)82 2)84 

XXII. DIVISION 

A. 2)86 2)88 3)33 3)36 3)39 3)60 

5. 3)66 3)69 3)90 3)93 3)96 3)99 

a 4)44 4)48 4)80 4)84 4)88 5)55 







XXIII. 


DIVISION 




^. 


55-s-5 = 


60 + 5 = 


66 + 6 = 


72 + 6 = 


5. 


77-^-7 = 


84+7 = 


88 + 8 = 


96 + 8 = 


c. 


99 H- 9 = 


50 + 2 = 


75 + 3 = 


100 + 4 = 


J). 


50 + 1 = 


100 + 2 = 


70 + 2 = 


90+2 = 


E. 


10 + 1 = 


11 + 1 = 


22+1 = 


44 + 1 = 

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GRADE III. SECOND SERIES 27 

XXIV. PROBLEMS: AT PLAY 

1. Mother gives to Mary and her 4 friends an old 
clothesline for jump ropes. It is 30 feet long. If the 
clothesline is cut into equal lengths so that each girl 
has one, how long will each rope be? 

2. In Arthur's yard there is a pile of old bricks. He 
counts them and finds there are 99 bricks in the pile. 
He makes 3 houses of equal size of the bricks, putting 
bricks into each house. 

3. Eleanor's garden plot is square. It is 20 feet 
around. Each side must then be feet. 

4. Esther has 5 dolls at her doll-party. Mother gives 
her 30 cakes, which she divides equally among her dolls. 
How many cakes does each doll have? 

5. If 3 boys pay equally for a kite string that costs 
18 cents, each boy's share is cents. 

6. The twine is 90 feet long. If the boys divided it 

equally among themselves, each boy would have 

feet of string. (Would this be enough for a kite 
string ?) 

7. How much money will Martha spend if she divides 
75 cents her uncle gives her into 3 parts and spends 
one of them? 

8. Harriet has 25 cents, which she spends for little dolls 
that cost 5 cents each. How many dolls does she buy? 

Additional Work. Each pupil should write out and bring to class 
a similar problem of his ovm. 

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28 PRACTICE EXERCISES IN MENTAL ARITHMETIC 
XXV. PROBLEMS: MISCELLANEOUS 

1. Two boys buy a football together. One gives 50 

cents towards it, the other 25 cents. The ball costs 

cents. 

2. When the two boys come out of the store they 
find 20 other boys waiting to play with them. That 
makes boys ready for a game. 

3. The boys are divided into 2 equal groups. That 
makes two teams of boys each. 

4. One side makes 12 points the first half, and the 

same side makes 7 points the second half, or points 

in all. 

5. When the game is over, one side has made 30 
points and the other side has made twice as many. How 
many points has the other side made ? 

6. While the boys are playing football the girls are 
playing bean bag. There are at first 13 white bags and 

3 blue bags, or bags in all. 

7. Hattie joins the company and brings 4 white and 

4 yellow bean bags. How many of each color do the 
girls now have to play with? 

8. Hattie scores 7 points, and on a second try she 
scores 8 points. Her score then stands points. 

9. Marion scores 8 points at first and then 8 points. 
How many points has she then? (Do this in two ways.) 

Additional Work, Each pupil should write out and bring to class 
a similar problem of his ovm. 

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GRADE III. SECOND SERIES 29 

XXVI. PROBLEMS: MISCELLANEOUS 

1. One beautiful fall day a number of children go 
with their parents on a picnic. If there are 7 boys 
and 7 girls, how many children are there ? (Do this in 
two ways.) 

2. Each boy takes a lunch basket in each hand. There 

must have been baskets in all, for the parents had 

packed their lunches in the children's baskets. 

3. Twenty people sat down to lunch. As there were 
14 children, there must have been parents. 

4. It was found that 4 children had brought 3 apples 
apiece. So there were apples for luncheon. 

5. If there were 26 ham sandwiches and 16 chicken 
sandwiches, how many more were there of the ham than 
of the chicken sandwiches? 

6. Each of the 14 children ate 2 olives. How many 
olives were eaten by the children ? (Do this in two ways. 
Which way is easier?) 

7. There were 6 olives left. The parents ate these, 
each having the same number. How many did each of 
the 6 parents have ? (Do this in two ways. Which way 
is easier ?) 

Additional Work. Each pupil should write out and bring to class 
a similar problem of his otvn. 

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GRADE III. THIRD SERIES 

Note. These exercises give practice in recognizing at a glance the sum 
of two-figure numbers. Pupils should give the sums without naming the 
numbers. 









I. ADDITION 








A. 10 


20 


30 


40 50 35 


25 


25 


10 


10 


20 


30 


40 50 35 


25 


75 


11 



B. 11 12 13 14 15 10 10 10 10 
111213141512131415 

II. ADDITION 

A. 10 10 10 10 10 10 10 10 10 
16 17 18 19 20 30 40 50 60 



B. 10 


10 


10 


20 


20 


20 


20 


20 


20 


70 


80 


90 


30 


40 


50 


60 


70 


80 


C. 22 


33 


44 


21 


31 


41 


32 


33 


34 


22 


33 


44 


21 


31 


41 


32 


33 


34 



III. ADDITION 

A. 30 + 40 = 30 + 50 = 30 + 60 = 30 + 70 = 

B. 40 + 50 = 40 + 60 = 11 + 12 = 11 + 13 = 
a 11 + 20= 11 + 14= 11 + 22= 11 + 15 = 
D. 11 + 18= 11 + 16= 11 + 17= 21 + 18 = 



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GRADE III. THIRD SERIES 31 

IV. PROBLEMS: AT SCHOOL 

1. If in Harriet's schoolroom there are 22 boys and 
21 girls, there are pupils present. 

2. The room is divided into two classes. In one 
class there are 10 boys and 11 girls. How many pupils 
are there in this class? 

3. How many are there in the second class, where 
there are 10 girls and 12 boys? 

4. One day in Harriet's room there are 32 pupils and 

in Minnie's room 32 pupils. In both rooms there are 

pupils. (In what two ways can you do this example?) 

5. If this school has a 20-minute recess in the morn- 
ing and a 15-minute recess in the afternoon, how many 
minutes are given to recess during the day? 

6. How long is the blackboard space in a room if 
the front board is 33 feet long and the side board 32 
feet long? 

7. In Minnie's room there were 28 pupils present on 
Monday and 11 pupils absent. What is the membership 
of the school? 

8. Jerry is asked to count the reading books for his 
class. He finds two sets. One set has 25 books and 
another set has 25 books. How many books does he 
find ? (Do this in two ways.) 

9. How much time is given to arithmetic in Harriet's 
room if one class recites 12 minutes and the other 14 
minutes ? 

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82 PRACTICE EXERCISES IN MENTAL ARITHMETIC 

Note. Pupils should learn to recognize these differences at a glance. 
The limit of numbers used is the same as in the three preceding exercises. 



V. SUBTRACTION 

A. 10 16 70 20 17 80 30 80 60 
10 10 10 20 10 10 30 20 10 



!. 70 


50 


11 


90 


11 


25 


12 


15 


12 


10 


10 


11 


10 


10 


25 


12 


10 


10 



VI. SUBTRACTION 
A. 13 18 75 40 14 60 14 15 13 



13 


10 


25 


10 


14 


20 


10 


15 


10 


B. 50 


30 


30 


35 


40 


50 


20 


40 


19 


20 


10 


20 


35 


20 


50 


10 


40 


10 


C. 22 


34 


42 


24 


33 


45 


36 


32 


37 


20 


33 


41 


21 


30 


44 


35 


12 


27 



VII. SUBTRACTION 
^.40-30= 50-30= 60-30= 70-30 = 

B. 50 - 40 = 60 - 40 = 12 - 11 = 13 - 11 = 

C. 21-11= 14-11= 22-11= 15-11 = 

D. 18-11= 16-11= 17-11= 33-11 = 

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GRADE III. THIRD SERIES 88 

VIII. PROBLEMS: AT SCHOOL 

1. If there are 40 children in Ehner's school and 20 of 
these are boys, there must be girls. 

2. How many pupUs are present in Elmer's school if 
40 belong and 10 are absent? 

3. When 11 children stay in at recess on a rainy day, 
how many go out if 38 have come to school? 

4. Elmer starts to school 35 minutes before it begins. 
It takes him 25 minutes to go to school. How long does 
he have to play before school begins? 

5. If 40 children belong in Elmer's school and 45 belong 

in Jenny's, there are more pupils in Jenny's school 

than in Elmer's. 

6. If in one class there are 15 boys and 11 girls, there 
are more boys in the class than girls. 

7. The teacher asks Sam to put 23 pieces of chalk 
around the blackboards for the class to use. He can find 
only 13 pieces in the box. How many more does he need ? 

8. How much longer is the morning recess than that 
in the afternoon if the afternoon recess is 15 minutes 
long and the morning one is 20 minutes long? 

9. The noon period is 90 minutes long. Susan can go 
home, eat her dinner, and be back again in 60 minutes. 
She has minutes to spare. 

Additional Work. Each pupil should write out and bring to class 
a similar problem of his oum. 

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34 PRACTICE EXERCISES IN MENTAL ARITHMETIC 

Note. Exercises to train pupils to think (without conscious reckoning) 
the sum of two-figure numbers. No "carrying"; sums of units and of 
tens less than 10. Pupils should think from left to right. 









IX. ADDITION 




. 




A. 23 


24 


25 


26 27 24 


23 


23 


32 


32 


42 


52 


62 72 24 


23 


55 


45 



B. 


32 


32 


33 


33 


33 


34 


34 


34 


35 




57 


63 


44 


55 


66 


53 


23 


44 


63 










X. ADDITION 








A. 


35 


45 


45 


45 


46 


46 


46 


47 


47 




42 


22 


33 


44 


33 


22 


53 


12 


42 


B. 


47 


48 


52 


53 


54 


55 


55 


56 


56 




52 


31 


25 


35 


45 


22 


44 


23 


33 


C. 


42 


32 


53 


35 


33 


75 


13 


18 


35 




37 


43 


24 


62 


45 


24 


65 


41 


44 



XI. ADDITION 

A. 56 + 33= 62 + 35= 63 + 36= 64 + 24 = 

B. 65 + 34= 66 + 22= 66 + 33= 72 + 23 = 

a 72 + 24= 81 + 18= 72 + 25= 72 + 17 = 

2>. 72 + 27= 55 + 14= 77 + 22= 52 + 33 = 



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GEADE III. THIRD SERIES 36 

XII. PROBLEMS: AT SCHOOL 

1. In a certain school there were 45 readers of one 
kind and 44 readers of another kind. How many readers 
were there of the two kinds? 

2. In a two-room building 72 children were present 
and 16 were absent. There must have belonged in the 
two rooms children. 

3. How many pupils belonged in a school where 23 
were girls and 31 were boys? 

4. On a rainy day the teacher counted 17 pupils who 
did not go out at recess. There were 22 on the play- 
ground. How many were present that day? 

5. If at the close of the school year 66 arithmetics 
were put away in the storeroom and 23 were sent away 

to be repaired, there must have been arithmetics in 

the school at the close of the year. 

6. How many desks are there in a room where there 
are 22 on one side and 22 on the other side? (Think 
this problem in two ways.) 

7. A sheet of paper is to be passed to each of the pupils 
in a class of 24 and a sheet to each in a class of 23. How 
many sheets must be counted out for both classes ? 

8. The teacher has 43 sheets and sends to the prin- 
cipal for 15 sheets more. Is that enough to give a 
sheet to each one in a class of 48 pupils? 

Additional Work. Each pupil should write out and bring to class 
a similar problem of his own. 

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36 PRACTICE EXERCISES IN MENTAL ARITHMETIC 

Note. Exercises to train pupils to think the differences of two-figure 
numbers. No " borrowing " is required ; therefore the differences should be 
thought from left to right as one reads. 



XIII. SUBTRACTION 

A. 41 49 42 48 59 51 58 52 45 
20 19 31 24 42 20 16 31 23 



70 


57 


46 


49 


47 


62 


53 


52 


63 


30 


35 


11 


23 


24 


31 


43 


22 


23 



XIV. SUBTRACTION 

A. 55 64 65 56 66 72 73 67 68 
30 44 60 24 33 40 31 24 34 



B. 80 


74 


79 


75 


89 


76 


82 


99 


77 


40 


22 


45 


25 


41 


46 


82 


22 


11 


C. 88 


99 


66 


55 


77 


87 


78 


99 


88 


55 


25 


43 


22 


77 


77 


77 


66 


34 



XV. SUBTRACTION 

A. 75-35= 78-54= 88-44= 83-30 = 

5. 84-42= - 85-24= 91-50= 98-44 = 

C. 92-41= 86-35= 93-33= 97-65 = 

B. 87-52= 94-22= 95-15= 96-72 = 



Digitized byCjOOQlC 



GRADE III. THIRD SERIES 37 

XVI. PROBLEMS: AT SCHOOL 

1. Of a pile of 95 paper pads 35 were distributed to the 
pupils. How many pads remained in the pile ? 

2. If a school of 42 pupils uses 1 pad of white paper 
and 84 pads of yellow scratch paper a month, they use 
more yellow than white pads. 

3. It requires 37 rubber erasers to supply one to each 
pupil in a school. The teacher finds she has only 22 erasers. 
How many more does she need for her school ? 

4. In Jerry's reading class of 25 children there are not 
enough books to go around. If 13 children listen while 
the others read, how many books are there? 

5. Hester is in a class of 23 pupils. The teacher asked 
her to take enough arithmetics from a pile of 37 so that 
each of her class could have one. There are two ways 
for her to solve her problem. Which is the easier way? 

6. Four packages of pencils contain 48 pencils. John is 
asked to take enough pencils to supply one to each of his 
class of 38 pupils. John can proceed in two ways. Which 
is the easier ? 

7. At the end of the year the teacher finds that of the 
45 desks in her room 13 have been so badly scratched that 
they must be repaired. How many careful pupils were there 
in the school ? 

Additional Work. Each pupil shovid write out and bring to class 
a similar problem of his otm. 

Digitized byCjOOQlC 



38 PRA.CTICE EXERCISES IN MENTAL ARITHMETIC 

Note. These are reciew exercises in multiplication. Pupils should 
recognize products at a glance. 



XVII. MULTIPLICATION 



A. 


1 


10 


44 12 


25 32 


23 


33 


50 




1 


1 


2 3 


1 2 


2 


J 


2 


B. 


70 


34 


20 30 


21 32 


21 


11 


25 




1 


2 


3 2 


3 3 


4 


4 


4 








XVIII. MULTIPLICATION 








A. 


12 


11 


22 12 


9 11 


8 


12 


7 




_i 


_5 


A A 


_6 J_ 


9 


6 


8 


B. 


10 


12 


8 7 


5 3 


6 


11 


6 




9 


8 


8 9 


8 9 


8 


6 


7 


a 


9 


9 


8 8 


9 9 


7 


5 


4 




12 


8 


7 12 


9 7 


12 


9 


9 








XIX. MULTIPLICATION 








A. 


6x 


6 = 


12x7 = 


4x9 = 




9x9 = 




B. 


9x 


11 = 


5x9 = 


8x4 = 




7x5 = 




c. 


8x 


3 = 


7x7 = 


7x4 = 




9x1 = 




D. 


20) 


<2 = 


30x3 = 


22x3 = 




33 X 2 = 




E. 


44) 


<1 = 


18x1 = 


60x1 = 




20x5 = 












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^. 












1 



GRADE III. THIRD SERIES 39 

XX. PROBLEMS: AT SCHOOL 

1. If there are 25 pupils in your class and each pupil 

uses 3 pads of paper in a term, it will take pads 

to supply the class. 

2. The teacher gives a box of 8 colored crayons to 
each child in a class of 12 children. How many crayons 
were there altogether? 

3. If 30 sheets of paper were cut into 3 pieces each, it 
would be enough to supply pupils with one piece each. 

4. There are 2 rooms in Jacob's schoolhouse. If in 

each room there are 42 desks, there must be desks 

in the two rooms. (Think this in two ways.) 

5. A janitor collects 8 bushels of waste paper each day. 
He will then collect bushels in a school week. 

6. Elizabeth is in a class of 23 children. They use 
3 different reading books in one term. The teacher will 
ne6d to order readers for that class for the term. 

7. During the year in one room in a building 20 
packages of composition paper are used. How many 
packages must be supphed to a 5-room building if each 
room uses the same amount? 

8. If there are 22 books in each of 4 sets, how many 
covers are needed if each book is to be covered? 

9. At the close of the year in one school 9 books were 
found to be worn out in each of 6 different sets of readers. 
Then new books should be bought for those sets. 

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40 PRACTICE EXERCISES IN MENTAL ARITHMETIC 

Note. These are review exercises in division. Pupils should recognize 
the quotients at a glance. 

XXI. DIVISION 

A. ijl 1)2 1)3 iJIO 2)18 2)22 

B. 3)30 2)24 3)36 3j60 3)39 3)66 
a 3)90 3)63 3)93 3)69 4)16 4)i0 

XXII. DIVISION 

A. 4)20 4)44 4)48 5)30 5)40 5)55 

5. 6)18 6)36 7)21 7)35 6)24 6)66 

C. 7)28 6)42 7)49 6)72 7)56 8)24 



^. 84 + 7 = 


32 H- 8 = 


/x V x«xv>rxi 

27 + 9 = 


48 + 8 = 


5. 36+9 = 


63 + 9 = 


96 + 8 = 


80+8 = 


C. 99 + 9 = 


54 + 9 = 


81+9 = 


64 + 8 = 


2). 45-*-9 = 


72 -.-8 = 


25 + 1 = 


99 + 3 = 


.E. 77 H- 7 = 


77 + 1 = 


20+1 = 


75 + 3 = 






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GRADE III. THIRD SERIES 41 

XXIV. PROBLEMS: AT SCHOOL 

1. The principal of a school has ordered 48 erasers 
for use at the blackboard. If these are divided equally 
among 4 rooms, each room will receive erasers. 

• 2. If there were 8 rooms among which the 48 erasers 
were to be equally distributed; how many would each 
room receive? 

3. There are 42 desks to be put mto a schoolroom. If 
they are arranged in 6 rows, in each row there will 
be desks. 

4. There are 3 classes in a school to be supplied with 
reading books, and 60 books are ordered. If the same 
nmnber of books is given to each class, each will receive 
books. 

5. There are 36 children in a school. The teacher 
separates them into 6 equal groups. How many children 
are in each group? 

6. In a school of 44 pupils there are two classes of 

equal size. If one class is dismissed pupils remain 

at their seats. 

7. The teacher gives the class in arithmetic slips of 
paper 9 inches long. She says, '^Divide your slips into 
3 equal parts." How long will each part be? 

8. If the 9-inch strips were divided into 9 equal parts, 
each part would be inch long. 

Additional Work. Each pupil should write out and bring to class 
a similar problem of his otvn. 

Digitized byCjOOQlC 



40 PRACTICE EXERCISES IN MENTAL ARITHMETIC 

Note. These are review exercises in division. Pupils should recognize 
the quotients at a glance. 

XXI. DIVISION 



A, 1)1 1)2 1)3 l)IO 2)18 2)22 

B. 3J3O 2)24 3)36 3)60 3)39 3)66 



c. 3)90 


3)63 3)93 


3)69 


4)16 


4)40 




XXII. DIVISION 






^. 4)20 


4)44 4)48 


5)30 


5)40 


5)55 


B. 6)18 


6)36 7)21 


7)35 


6)24 


6)66 


C. 7)28 


6)42 7)49 


6)72 


7)56 


8)24 




XXra. DIVISION 






^.84 + 7- 


s-> ^ s = 


27 H- 9 = 


48 + 8 = 


B. 36+9- 


IW ^ 1» = 


iW-^B-* 


^80fS= , 


a 99 -•- i> = 


64 * 9 = 


?!- 


Ig4^ 


S^ 


Z). 45+9- 


T-i -^ S - 


%M 


u 


F 


J. 77+7 = 


t: + 1 « 


^ 


■ 





iGbogk 
1^ 




4t 



^5ui,z ILL TH:s:t, xr,;c(zji 



X, "^ 



a?^ 



L'X IfOLi. aTfL ii 









• v.* .' 



>.• •£.< 



^ ^Ji^f?^ S?- ^« 






n 




M i> 




Digitized by VjOOQ IC 



42 PRACTICE EXERCISES m MENTAL ARITHMETIC 
XXV. PROBLEMS: MISCELLANEOUS 

1. If a school day is 5 hours long, how many hours are 
there in a school week ? 

2. In some schools there are 30 hours in a school week. 
In these schools a school day is hours long. 

3. When schools keep 20 days each school month, at 

the end of a term of 3 months the schools have kept 

days. 

4. Harry was out of school sick for 20 days during a 
period of 80 school days. How many days did he attend 
school during that time? 

5. Judith is planning her school garden. She has a 
strip of ground 18 feet long. How many '' hills " can she 
plant in a row if she plants them 3 feet apart ? 

6. If Judith plants her hills 2 feet apart she will have 
9 hills. How many seeds will she need if she puts 4 seeds 
in each hill ? 

7. Joe planted tomatoes in his school garden. He has 
6 vines and picks 6 good tomatoes from each vine. His 
crop of good fruit is then . tomatoes. 

8. Jerry picks 45 good tomatoes from his vines. He 

sells 25 of them to a neighbor and gives the rest, or 

tomatoes, to his mother. 

9. In a two-room school there are 40 boys and 35 girls. 
How many pupils belong to this school? 

Additional Work. Each pupil should write out and bring to class 
a similar problem of his own. 

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GRADE III. THIRD SERIES 43 

XXVI. PROBLEMS: MISCELLANEOUS 

1. Ethel's class in school is given, 3 times a week, 5 
words to learn to spell. At the end of the week the class 
has studied words. 

2. At the end of a school month of 4 weeks Ethel's 
class in spelling has studied 60 words. Of these, 20 words 
did not need very hard study, for Ethel knew them pretty 
well already. How many hard words were there to be 
studied ? 

3. There are 26 letters in the alphabet. Henry can write 

the capital form of 22 of them. He is uncertain about 

capital forms. 

4. On page 40 there are 56 examples. If you make a 
mistake in 16 of them, how many can you do correctly? 

5. If by 4 minutes' study you have mastered the 16 
difficult examples, how many have you mastered each 
minute ? 

6. There are three ways in which you can find out the 
number of examples in Exercise XXIII, page 40. What 
are the three ways and which is the best ? 

7. When you take 20 minutes to learn a lesson that you 
can learn in 15 minutes, how much time have you wasted ? 

8. If you can give the correct answer to each of the 
examples in Exercise XXIII, page 40, in 3 seconds, how 
long will it take you to do the entire exercise ? 

Additional Work. Every pupil should write out and bring to class 
a similar problem of his own. 

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GRADE III. FOURTH SERIES 

Note. The Fourth Series consists of exercises in using combinations 
that should now be familiar, but they appear here under the mask of 
United States money symbols. 

I. ADDITION 

A. $0.03 $0.04 $0.02 $0.05 $0.08 $0.09 
.03 .04 .02 .05 .02 .01 



£. 


$0.05 
.02 


$0.04 
.01 


$0.05 
.01 


$0.09 
.02 


$0.04 
.02 


$0.01 
.01 








II. ADDITION 






A. 


$0.06 
.01 


$0.03 
.02 


$0.04 
.03 


$0.03 
.01 


$0.08 
.01 


$0.06 
.02 


B. 


$0.07 
.01 


$0.06 
.03 


$0.05 
.04 


$0.06 
.06 


$0.07 
.07 


$0.02 
.01 








III. ADDITION 






A. 


$0.07 
.02 


$0.05 
.03 


$0.09 
.09 


$0.01 
.03 


$0.01 
.08 


$0.02 
.06 


B. 


$0.01 
.07 


$0.03 
.06 


$0.04 
.05 


$0.01 
.02 


. $0.02 
.07 


$0.03 
.05 


a 


$0.06 
.06 


$0.07 
.07 


$0.09 
.09 


$0.01 
.03 


$0.03 
.04 


$0.02 
.03 



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GRADE III. FOURTH SERIES 45 

IV. PROBLEMS: EARNING, SAVING, AND SPENDING 

1. If Ralph puts into his bank $0.05 of the money 
he received for doing errands, and the rest, amounting 

to $0.03, he spends for candy, he must have earned 

doing errands. 

2. Ralph's little brother Tim helped him shovel snow 
from the sidewalk, and for this Ralph gives him at one 
time $0.01 and at another time $0.02. How much does 
little Tim earn in this way? 

3. Joan is paid $0.02 at two diflEerent times for doing 
errands for the neighbors. For these two errands she 

receives . (In what two ways can you do this 

problem. Is one way easier?) 

4. When Ralph has spent $0.05 for a ticket to a 
moving-picture show and $0.02 for gum, how much 
money has he spent? 

5. Francis decides to put $0.09 aside in his Christmas- 
present fund. This is half of what he earned during 
the week. How much did he earn? (Do this problem 
in two ways.) s 

6. Ralph and Francis go to the drug store. Francis 
spends $0.05 for an ice-cream cone and Ralph spends 
the same amoimt for a soda. The clerk received from 
both boys . (Do this in two ways.) 

7. How much money has Joan after she has foimd a 
nickel if she already had $0.03 in her pocketbook? 

Additional Work. Each pupil should write out and bring to class 
a similar problem of his own. 

Digitized byCjOOQlC 



46 PRACTICE EXERCISES IN MENTAL ARITHMETIC 

Note. The following are exercises in recognizing the more difl&cult 
addition combinations under the mask of United States money symbols. 



V. ADDITION 

A. $0.07 $0.09 $0.07 $0.08 $0.08 $0.07 
.05 .05 .03 .04 .08 .04 



B. 


$0.09 
.03 


$0.08 
.03 


$0.06 
.04 


$0.06 
.05 


$0.07 
.06 


$0.09 
.06 








VI. ADDITION 






A. 


$0.09 
.08 


$0.09 
.04 


$0.08 
.06 


$0.08 
.05 


$0.08 
.07 


$0.09 
.07 


B. 


$0.04 
.07 


$0.08 
.08 


$0.04 
.08 


$0.03 
.07 


$0.05 
.09 


$0.05 
.07 


C. 


$0.03 
.09 


$0.05 
.06 


$0.03 
.08 


$0.06 
.07 


$0.04 
.06 


$0.06 
.09 



VII. ADDITION 

A. $0.05 + .08 = $0.07 + .09 = $0.07 + .08 = 

B. $0.06 + .08 = $0.08 + .09 = $0.09 + .05 = 

C. $0.09 + .04 = $0.07 + .05 = $0.08 + .06 = 

D. $0.08 + .07 = $0.09 + .06 = $0.09 + .07 = 

Digitized byCjOOQlC 



GRADE III. FOURTH SERIES 47 

VIII. PROBLEMS: EARNING, SAVING, AND SPENDING 

1. When Lois has saved $0.09 and has received $0.08 
as a gift, she has that she can put in the bank. 

2. Frank has $0.08 and he earns $0.08 raking leaves 
from the yard. How much has he that he can use towards 
the purchase of a bat ? (Do this in two ways.) 

3. Frank and Arthur want to start a play store. Frank 
can put into the partnership $0.05 and Arthur can put in 

$0.07. Together they have with which to buy things 

for their store. 

4. If Lois spends $0.04 for cookies for her doll's party 
and $0.06 for fruit, how much does her party cost? 

5. How much does Lois earn all day Saturday if her 
mother gives her $0.06 for helping her in the morning, 
and in the afternoon a neighbor gives her $0.07 for taking 
the baby for a ride in the baby carriage ? 

6. Arthur's father agrees to give him $0.07 a week to 
keep his mother supplied with coal for the kitchen stove. 
How much does he receive at the end of two weeks ? (Do 
this in two ways. Which way do you prefer ?) 

7. On the first day of December Frank and Lois begin to 
think of Christmas. Frank counts his money. It amounts 
to $0.09. Lois counts hers and says that she has $0.07. 
How much do they have together with which to buy 
Christmas presents? 

Additional Work. Each pupil shoidd write out and bring to class 
a similar problem of his own. 

Digitized by VjOOQ IC 



48 PRACTICE EXERCISES m MENTAL ARITHMETIC 

Note. The following are exercises in recognizing dUSerences of what 
should now be familiar combinations, but under the mask of United States 
money symbols. 

IX. SUBTRACTION 

A. $0.09 $0.01 $0.04 $0.08 $0.05 $0.09 

.01 .01 .02 .02 .05 .02 

B. $0.05 $0.06 $0.08 $0.03 $0.04 $0.06 

.01 .02 .01 .01 .03 .01 



X. SUBTRACTION 



A. $0.03 
.02 


$0.04 
.01 


$0.05 
.02 


$0.08 
.03 


$0.09 
.05 


$0.07 
.02 


B. $0.07 
.05 


$0.09 
.05 


$0.07 
.03 


$0.08 
.04 


$0.08 
.08 


$0.07 
.04 


a $0.09 
.09 


$0.03 
.01 


$0.06 
.04 


$0.05 
.03 


$0.06 
.03 


$0.06 
.06 



XL SUBTRACTION 

A. $0.09 - .03 = $0.08 - .03 = $0.06 - .04 = 

B. $0.07 - .06 = $0.09 - .04 = $0.09 - .08 = 
a $0.09 -.07= $0.08 -.07= $0.08 -.05 = 
D. $0.09 -.05= $0.07 -.05= $0.03 -.03 = 

Digitized byCjOOQlC 



GRADE III. FOURTH SERIES 49 

XIL PROBLEMS: EARNING, SAVING, AND SPENDING^ 

1. Jerry earns $0.10 and spends $0.09. He has 

left. 

2. If Rosa has $0.08 in the bank and takes out $0.08, 
how many cents has she left in the bank? 

3. How much money does Joe have when he reaches 
the store if his mother gives him $0.07 and he loses 
$0.02 on the way? 

4. Joe reaches the store with $0.05 and buys a yeast 

cake for $0.03. The storekeeper should give him 

in change. 

5. When Jerry has saved $0.08 he decides to put 
$0.05 in his bank. He has then left to spend. 

6. Jerry and Joe have $0.07 each. How much more 
does Jerry have than Joe? 

7. Rosa goes to a candy shop. She can buy 3 candy 
balls for a cent or 2 chocolate creams for a cent. 
Which kind can she buy more of for a cent, and how 
many more? 

8. Joe can buy a pair of shoe strings for $0.05 or 
two pairs for $0.09. How much will he save by buy- 
ing two pairs at one time? (You can do a part of this 
in two ways. Which is the better way?) 

Additional Work. Hack pupil should write out and bring to class 
a similar problem of his own. 

Digitized byCjOOQlC 



60' PRACTICE EXERCISES IN MENTAL ARITHMETIC 

Note. The following are exercises in thinking the products of what 
should be familiar combinations, but under the mask of United States 
money symbols. They contain the thirty-six combinations of numbers to 
12 X 9 (out of a possible seventy-two) that give the least difficulty. 



XIII. MULTIPLICATION 



A. 


$0.10 
1 


$0.08 
2 


$0.02 
2 


$0.02 
1 


$0.05 
1 


$0.12 
1 


B. 


$0.06 
1 


$0.07 
1 


$0.03 

2 


$0.09 
1 


$0.03 
3 


$0.05 

2 






XIV. 


MULTIPLICATION 






A. 


$0.03 
1 


$0.04 

1 


$0.11 
1 


$0.10 

2 


$0.10 

4 


$0.04 
2 


B. 


$0.05 
5 


$0.07 
2 


$0.10 
3 


$0.09 
2 


$0.01 

1 


$0.11 
2 


C. 


$0.05 
3 


$0.06 
2 


$0.05 
4 


$0.08 
2 


$0.10 
5 


$0.07 
3 



XV. MULTIPLICATION 

^.$0.04x3= $0.04x4= $0.10x6= $0.12x2 = 

B. $0.10x8= $0.10x7= $0.03x5= $0.02x6 = 

C. $0.04x5= $0.02x8= $0.03x7= $0.03x4 = 

D. $0.02x12= $0.02x11= $0.02x9= $0.02x7 = 

Digitized by VjOOQIC 



GRADE III. FOURTH SERIES 51 

XVI. PROBLEMS : EARNING, SAVING, AND SPENDING 

1. Ned earns $0.25 on Monday and $0.25 on Tuesday ; 
how much has he earned by Tuesday night? (Do this in 
two ways. Which way do you prefer ?) 

2. Ned has $0.04 and his sister Lucy has four times as 
much. Then Lucy has . 

3. Joseph charges $0.10 for cleaning snow from ^ 
sidewalk. If he cleans 5 sidewalks during one snow- 
storm, how much does he earn? (Do this in two ways 
and tell which is the easier way.) 

4. Jenny has $0.08 in her bank and Mary, her older 
sister, has eight times as much. How much has Mary? 
(Do this in two ways. Which is the better way?) 

5. Ned goes to the store to buy Christmas cards. He 
selects those that sell for $0.03 each. He buys 7 of them 
and pays . 

6. Lucy buys 4 cards that cost $0.05 each. How much 
does she pay ? 

7. If Jenny earns $0.12 a week, how much will she earn 
in a fortnight ? 

8. Little Tom helps his big brother sell newspapers. 
A profit of $0.01 is made on each paper. When Tom has 
sold 12 papers he has made . 

Additional Work. Each pupil should write out and bring to class 
a similar problem of his oum. 

Digitized byCjOOQlC 



62 PRACTICE EXERCISES IN MENTAL ARITHMETIC 

Note. The following are the products of the more difficult combination^ 
of numbers to 12 x 9 arranged in the probable order of progressive difficulty. 



XVII. MULTIPLICATION 



A 


$0.10 
9 


$0.11 
3 


$0.06 
3 


$0.11 
5 


$0.06 
6 


$0.11 
4 


B. 


$0.06 
4 


$0.08 
5 


$0.11 

7 


$0.06 
5 


$0.11 
6 


$0.08 
3 






XVIII 


. MULTIPLICATiON 




A. 


$0.11 

8 


$0.09 
5 


$0.09 
3 


$0.07 
5 


$0.11 
9 


$0.12 
3 


B. 


$0.07 

4 


$0.08 
4 


$0.12 
4 


$0.09 
9 


$0.07 

7 


$0.12 
5 


a 


$0.07 
6 


$0.09 
4 


$0.08 
6 


$0.12 
6 


$0.08 
8 


$0.09 
6 



XIX. MULTIPLICATION 

A. $0.12x9= $0.09x8= $0.08x7= $0.12x7 = 

B. $0.09x7= $0.12x8= $0.06x8= $0.06x12 = 

C. $0.04x9= $0.06x9= $0.09x12*= $0.08x9 = 

D. $0.07x8= $0.07x12= $0.07x9= $0.08x12 = 

E. $0.25x4= $0.25x3= $0.25x2= $0.50x2 = 

Digitized byCjOOQlC 



GRADE III. FOURTH SERIES 53 

XX. PROBLEMS: EARNING, SAVING, AND SPENDING 

1. When Sam has sold 9 heads of lettuce from his 
garden for $0.05 a head, he has earned . 

2. When radishes are selling in the market for $0.03 

a bmich, Julius will save for his mother if he 

gives her 9 bunches out of his garden. 

3. Harriet works 4 hours one week in her garden. If 
her time is worth $0.08 an hour, what is the value of the 
time she has put into garden work diu'ing the week ? 

4. Sam is paid $0.12 for pulling 100 weeds out of 
the lawn. How much will be due him when he has 
pulled 800 weeds? (Is this too much or too little for 
pulling weeds?) 

5. Julius prefers to work by the hour and is paid at 
the rate of $0.11. After he has worked 9 hours he 
has earned . 

6. Sam puts in his bank $0.06 out of every $0.12 
he earns. After he has pulled 800 weeds he should put 
in his bank. 

7. From what he earns each horn- Julius takes $0.06 
to put away for Christmas presents. How much has he 
put aside after he has received pay for 9 hours' work? 

8. At Christmas time Harriet wishes to spend $0.25 
on a present for each of her 3 friends. How much 
money will she need? 

Additional Work. Each pupil sJumld write out and bring to class 
a similar problem of his own. 

Digitized byCjOOQlC 



64 PRACTICE EXERCISES IN MENTAL ARITHMETIC 

Note. The following are exercises in thinking the quotients of what 
should now be familiar combinations, bat under the mask of United States 
money symbols. The products in Exercises XVII-XIX are here used as 
dividends. 

XXI. DIVISION 



A. 9)$0.90 3)$0.33 3)$0.18 5)$0.55 6) $0.36 

B. 4)$(X44 4)$0^ 5)$0.40 7)$(X77 5j$0J0 
a 6)$0^ 3)1024 SJWSS 5j|0l5 3j|a27 

XXII. DIVISION 



^. 5)$0.35 9)10.99 3)$0.36 4)$0.28 4)$0.32 
B. 4)$0.48 9)$0.81 7)$0.49 5)$0.60 6)$0.42 



a 4)$0J6 6j$08 6)$0J2 8) $0.64 6)$0M 

XXIII. DIVISION 
A $1.08 -«- 9= $0.72 + 8= $0.56 +7= $0f84-s-7 = 

B. $0.63-*- 7= $0.96+8= $0.48 -i- 8= $0.72+12 = 

a $0.36 + 9= $0.54 + 9= $1.08 + 12= $0.72 + 9 = 

D. $0.56 + 8= $0.84+12= $0.63 + 9= $0.96 + 12 = 

E. $1.00 + 4= $0.75 + 3= $0.50 + 2= $1.00 + 2 = 

Digitized byCjOOQlC 



GRADE III. FOURTH SERIES 56 

XXIV. PROBLEMS: EARNING, SAVING, AND SPENDING 

1. Sam receives $0.45 for 9 heads of lettuce that he 
sells from his garden. How much does he receive for 
each head? 

2. Paul's mother would pay $0.27 for 9 bunches of 
radishes if she bought them at the store. If Paul sells 
those he' raises in his garden at the same rate, he will 
charge a bunch. 

3. Harriet thinks that when she has worked 4 hours 
in her garden she has put in work to the value of $0.32. 
This is at the rate of an hour. (Does Harriet esti- 
mate her work at too high a value ?) 

4. Paul is paid $0.99 for 9 hours' work. How much 
does he receive an hour ? (Is this good pay for a ten-year- 
old boy?) 

5. From the money Sam receives for pulling weeds he 
puts in his bank $0.48. He earns this money by pulling 
800 weeds. How much does he earn for his bank by 
pulHng 100 weeds? 

6. Paul has a Christmas fund of $0.54. He has taken 
it from the money he earned by working 9 hours. How 
much did he earn each horn- for his Christmas fund ? 

7. At Christmas time Harriet spends $0.75 for presents 
for her 3 friends. She pays the same for each present. 
Then she spends for each friend. 

Additional Work. Each pupil sTioiUd write out and bring to class 
a similar problem of his otvn. 

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56 PRACTICE EXERCISES IN MENTAL ARITHMETIC 
XXV. PROBLEMS: MISCELLANEOUS 

1. Uncle Reuben has a cherry tree. He tells John, 
Harry, and Ralph that he will give them $0.03 a quart 
to pick the cherries. John picks 10 quarts, Harry 12 
quarts, and Ralph 8 quarts. How much does Uncle Reuben 
pay each boy ? 

2. Uncle Reuben sells 9 quarts of cherries for $0.81. 
What is the price for a quart? 

3. If the cherries cost $0.03 a quart to pick and they 

are sold for $0.09, Uncle Reuben makes a profit of 

on each quart that he sells. 

4. Uncle Reuben has a pear tree also. He agrees to pay 
the boys $0.11 a bushel to pick the pears. How much 
should Ralph receive for picking 4 bushels ? (Which is the 
easier of the two possible ways of doing this ?) 

5. If Harry works 6 hours picking pears and receives 
$0.66, how many pears did he pick during that time? 

6. Harry earns $0.09 while John is earning $0.07. 

Then he earns more than John does in the same 

time. 

7. If Harry earns $0.03 more than John does in an 

hour, he will be worth more than John at the end 

of 5 hours. 

Additional Work. Each pupil %hovld write out and bring to class 
a similar problem of his own. 



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GRADE HI. FOURTH SERIES 57 

XX VI. PROBLEMS: MISCELLANEOUS 

1. Eleanor, Bessie, and Hester have the same amount 
of money. They put it all in a pile and find that they 
have together $0.30. Then each one must have had . 

2. Eleanor spends $0.06 of her $0.10 and has left. 

3. Bessie loses $0.01 of her $0.10 and puts the rest in 
the bank. How much does she put in the bank ? 

4. Hester buys a ticket to the " movies " for $0.05. Of 
her $0.10 she has left. 

5. One day in the autumn the three girls with two of 
their friends rake the leaves from the lawn and receive 
$0.05 each from Hester's mother for doing it. Hester's 

mother paid for having the leaves raked from 

the lawn. 

6. Eleanor earned that same week $0.03 for going on 
an errand and $0.09 for helping mother with the dishes. 
At the end of the week how much did she have to add 
to the $0.05 earned in raking leaves? 

7. Bessie is given $0.02 a day if she is careful to throw 
the bedclothes over the foot of her bed every morning. If 
she remembers this every day, in 9 days she can earn . 

8. Ned and 4 of his friends form a saving club. 
Each promises to save $0.07 a week. If the boys keep 
their promise, how much will they together save in 
a week? 

Additional Work. Each pupil should write out and bring to class 
a similar problem of his own. 

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TO TEACHERS 

Before beginning the work of the fourth grade it will be well to 
make sure that the pupils are proficient in the third-grade work. 
It would not be amiss to go rapidly through all the abstract exer- 
cises with those classes that have not studied them. At least the 
Third and Fourth Series should be reviewed. 

If a review as extensive as that suggested is not desired, have 
pupils practice the combinations on pages 46, 52, and 54, for these 
are the combinations that give the most trouble. 



58 

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TABLES OP MEASURES 



Note. Only those items are included in the following tables that pupils 
of fourth-grade age are accustomed to meet in their out-of-school life. 

MEASURES OF LENGTH 

12 inches (in.) = 1 foot (ft.) 
3 feet (ft.) = 1 yard (yd.) 

MEASURES OF SURFACE OR AREA 

144 square inches (sq. in.) = 1 square foot (sq. ft.) 
9 square feet (sq. ft.) = 1 square yard (sq. yd.) 

MEASURES OF SOLIDS 

1728 cubic inches (cu. in.) = 1 cubic foot (cu. ft.) 
27 cubic feet (cu. ft.) = 1 cubic yard (cu. yd.) 



MEASURES OF LIQUIDS 
4 gills (gi.) = 1 pint (pt.) 
2 pints (pt.) = 1 quart (qt.) 
4 quarts (qt.) = 1 gallon (gal.) 

MEASURES OF TIME 



60 seconds (sec.) 
60 minutes (min.) 
24 hours (hr.) 
7 days (da.) 
365 days (da.) 
52 weeks (wk.) 
12 months (mo.) 



= 1 minute (min;) 
= 1 hour (hr.) 
= 1 day (da.) 
= 1 week (wk.) 
= 1 year (yr.) 
= 1 year (yr.) 
= 1 year (yr.) 



MEASURES OF PAPER 

24 sheets = 1 quire 

500 sheets = 1 ream 



59 



MEASURES OF DRY SUB- 
STANCES 

2 pints (pt.) = 1 quart (qt.) 
8 quarts (qt.) = 1 peck (pk.) 
4 pecks (pk.) = 1 bushel (bu.) 

MEASURES OF UNITED 
STATES MONEY 

10 mills =lcent(#orct.) 
10 cents = 1 dime (d.) 
10 dimes = 1 dollar ($) 
100 cents = 1 dollar 

COUNTING 

12 units = 1 dozen (doz.) 

144 units = 1 gross (gro.) 

12 dozen = 1 gross (gro.) 

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GRADE IV. FIRST SERIES 
I. READING NUMBERS 

Note. Pupils should not use the word and in reading whole numbers. 
242 should be read "two hundred forty-two"; 301 should be read "three 
hundred one." 



A. 113 


222 


345 


401 510 


635 


808 


B. 950 


708 


872 
II. 


698 384 
ADDITION 


999 


650 



Note. As in previous exercises pupils should see the sums without 
conscious calculation. 



A. 1 


1 


1 


1 


1 


1 


1 


1 1 


1 


1 


1 


1 


1 


1 


1 


2 2 


2 


3 


4 


5 


6 


7 


8 


2 3 


B. 1 


1 


1 


1 


2 


2 


2 


2 2 


2 


2 


2 


2 


2 


2 


2 


2 2 


4 


5 


6 


7 


2 


3 


4 


5 6 








III. 


ADDITION 






A. 3 


3 


3 


3 


3 


3 


3 


4 4 


2 


2 


2 


3 


3 


3 


1 


4 4 


3 


4 


5 


1 


3 


4 


5 


1 2 


B. 4 


2 


1 


1 


5 


3 


1 


2 4 


1 


6 


8 


7 


3 


4 


7 


6 3 


5 


2 


1 


2 


2 


3 


1 

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1 2 

Google 



GRADE IV. FIRST SERIES 61 

IV. PROBLEMS: AT HOME 

1. John lives at 205 Edgewood Avenue, Mary at 444 
South Street, and Harry at 520 Stanley Road. (Be sure 
that you can read these numbers correctly.) 

2. Harold lives on a farm. In April his father put 
into the chicken incubator 912 eggs. In three weeks 
887 chickens were hatched. Read the numbers correctly. 

3. Sarah lives in the country. She goes 2 miles to 
school, 3 miles farther to the village, and 1 mile beyond 

the village to the railroad station. The station is 

miles from Sarah's home. 

4. Mother sends Edith to the store to buy Christmas 
presents. How many dolls does she buy if she buys 2 
for her little sister, 2 for her cousin Lottie, and 4 for 
the neighbors' children? 

5. Frank coimts up the number of children whom he 
wishes to invite to his party. There are 3 boy friends 
and 3 girl friends besides his 2 sisters. How many does 
he invite? 

6. How many quart jars of preserves does Julia's 
mother make if she puts up 7 jars of peaches, 2 jars 
of pears, and 1 jar of plums? 

7. Julia goes to her aunt's home to make a visit. It 
takes a day to go, she spends 5 days there, and it takes 

a day to return. Then Julia spends days away 

from home. 

Additional Work. Each pipil should vnrite out and bring to class 
a similar problem of his ovm. 

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62 PRACTICE EXERCISES IN MENTAL ARITHMETIC 
V. READING NUMBERS 

^. I n in IV V VI VII viii 

B. IX X XI XXII XXXIII XL XLI XLV 

C. XL VI XLIX L XIV XVI XXVII XXXVIII 

VI. ADDITION 

Note. Train pupils to see at a glance the two numbers that in sequence 
make 10 and then add the third number. The skill gained in this practice 
should be carried over into all column and line addition. 



A. 1 


1 


2 


2 


3 


O 


4 


4 


5 


1 


2 


3 


4 


5 


6 


7 


8 


9 


9 


8 


7 


6 


5 


4 


3 


2 


1 


B. 5 


4 


2 


3 


1 


8 


6 


9 


7 


5 


6 


8 


7 


9 


. 2 


4 


I 


3 


1 


4 


5 


1 


6 


7 


8 


4 


6 



VII. ADDITION 

A. 1 + 9 + 1= 2 + 8 + 3= 4 + 7 + 3= 5 + 5 + 5 = 

B. 4 + 6 + 7= 8 + 4 + 6= 7 + 6 + 4= 9 + 1 + 5 = 

C. 7 + 1 + 9= 9 + 8 + 2= 8 + 3 + 7= 7 + 3 + 9 = 

D. 6 + 7 + 3= 4 + 9 + 1= 8 + 2 + 5= 7 + 2 + 8 = 

E. 1 + 9 + 8= 7 + 3 + 7= 4 + 6 + 4= 2 + 8 + 2 = 



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GEADE IV. FIRST SERIES 63 

VIIL PROBLEMS: AT HOME 

1. Lilian and Joseph were playing school. Lilian was 
teaching Joseph to make Roman numbers. Here are some 
questions she asked him. Answer them if you can. 

a. How do you make the Roman number ^ve? 
&. What do you do to the Roman five to make the 
Roman four ? 

c. What do you do to the Roman five to make the 
Roman sir? 

d. How do you make the Roman teii ? 

6. Change the Roman ten to the Roman nine ; change 
it to the Roman eleven. 

2. Have pupils ask each other similar questions about 
Roman numbers. 

3. Joseph has a hen that hatched only 2 chicks from 
a dozen eggs. Joseph gave her 3 other chicks that had 
strayed from their mother, and 7 whose mother a hawk 
had carried off. This made chicks for the mother hen. 

4. Lilian collected 6 eggs from one nest, 4 from another 
nest, and 8 from a third nest. How many eggs did she 
find? 

5. There are three parts to the driveway from the street 
to the garage at Joseph's house. From the curbstone to 
the front fence is 4 feet. From the fence to the comer of 
the house is 6 feet. From the comer of the house to the 
garage is 7 feet. Then the driveway is feet long. 

Additional Work. Each pupil should vrrite out and bring to class 
a similar problem of his own. 

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64 PRACTICE EXERCISES IN MENTAL ARITHMETIC 
IX. COUNTING 

A. Count by 2's to 100. C. Count by 4's to 100. 

B. Count by 3's to 99. J). Count by 5'8 to 100. 

X. SUBTRACTION 
Note. Before taking this exercise review pages 20 and 22. 

A 5 15 15 25 25 7 17 
2 _2 12 _2 22 3 13 

B. 37 57 9 19 19 49 7 
23 43 2 _2 12 22 4 

C. 17 57 8 18 28 58 58 

4 54 § _§ 13 13 M 

B. 9 19 19 39 17 27 57 

5 _5 15 35 ^ 7 7 

XL SUBTRACTION 

A. 17-10= 18-13= 28-13= 28-23 = 

B. 48-43= 50-30= 75-25= 60-40 = 

C. 52-22= 33-11= 66-22= 55-33 = 

D. 77-22= 44-11= 50-25= 50-20 = 
^.41-11= 51-11= 57-7= 57-57 = 



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GRADE IV. FIRST SERIES 66 

XII. PROBLEMS: AT HOME 

1. Fred's mother had a basket of eggs from which she 
wished to sell 5 dozen. She asked Fred to count them out 
by 2's. Coimt them for Fred. Fred thought he could count 
them out more quickly by 3's. Why would he not count 
them out by 4's or 5's ? Could he easily count them out 
by 6's? 

2. From a bag containing 20 pounds of flour Fred's 
mother takes enough to do the Saturday baking. On 
weighing the bag later it is found to contain 14 pounds, 
so his mother must have used pounds. 

3. Mother asks Jenny to polish the knives, forks, and 
spoons. Of the knives there are 24, but 2 are kitchen 

knives that do not need polishing. That leaves 

knives to be polished. 

4. When Jenny has polished 12 knives there are 

knives left, but only knives remain to be polished. 

5. If there are 23 forks in all and 10 of them are steel 
while the rest are silver, how many are silver ? 

6. There are 48 spoons — some teaspoons and some table- 
spoons. Jenny picks out the tablespoons and finds that 
there are 14 of them. How many teaspoons are there? 

7. There are in all 93 articles to be polished. Jenny 
works an hour, and then there are still 50 articles to polish. 
She had polished articles in the hour. 

Additional Work. JEach pupil should write out and bring to class 
a similar problem of his own. 

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66 PRACTICE EXERCISES IN MENTAL ARITHMETIC 

XIII. READING NUMBERS 

Note. When reading dollars and cents the word and should be used at 
the period only, f 101.10 is read "one hundred one dollars and ten cents." 



A. $1.10 


$1.01 


$3.00 


$5.50 


$6.25 


B. $0.16 


$0.04 


$0.35 


$9.15 


$7.05 


C. $8.80 


$3.20 


$4.44 


$9.99 


$0.90 



XIV. MULTIPLICATION 

Note. Have pupils give the products as rapidly as they read a page of 
easy prose. Additional practice may be given by reversing the order of the 
numbers. 



A. 12 


9 


8 


12 


9 


9 


12 


12 


12 


_9 


8 


7 


_8 


9 


7 


11 


10 


7 


B. 8 


9 


9 


11 


9 


8 


12 


7 


12 


8 


5 


4 


10 


6 


4 


12 


7 


_6 


C. 12 


8 


7 


6 


8 


11 


7 


11 


8 


5 


6 


6 


6 


5 


_6 


4 


11 


3 



XV. MULTIPLICATION 

A 7x3= 12x4= 6x5= 11x7 = 

Al2x3= 9x3= 11x8= 6x4 = 

C. 8x2= 11x9= 11x3= 6x3 = 

D. 6x2= 10x6= 12x2= 9x2 = 



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GRADE IV. FIRST SERIES 67 

XVI. PROBLEMS: AT HOME 

1. If Jerry sleeps 9 hours every night for 5 nights, 

he will sleep hours in that time. How many hours 

will he sleep in 10 nights ? (In what two ways can you ' 
find the second answer? Which is the better way?) 

2. If Jerry lies in bed 6 minutes every morning after 

he is called, he loses in this way minutes in a 

week ; in 2 weeks he loses minutes. (Do this second 

part in three ways. Which is the best way?) 

3. Jerry spends 12 minutes every morning before 
school helping his mother. During the school week he 

spends minutes in this way. How many hours is 

this? 

4. The walk from the house to the sidewalk is 11 feet 
long. If Jerry clears this walk of snow 3 times in one 

month he has cleared in all feet of walk. If during 

the winter he clears this walk 9 times, he has during 

the winter cleared in all feet. (Do this second part 

in three ways. Which is the best way?) 

5. Mother's napkins are i foot square. Then each one 

contains square feet of cloth. A dozen napkins 

contain square feet of cloth. Three dozen contain 

square feet. (Do the last part in three ways, 

selecting the best.) 

Additional Work. Each pupil should write out and bring to class 
a similar problem of his ovm. 

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68 PRACTICE EXERCISES IN MENTAL ARITHMETIC 
XVII. READING NUMBERS 

A. $10.01 $25.10 $17.60 $38.19 $47.85 

B. $50.50 $60.05 $89.19 $75.25 $54.45 

C. $90.09 $98.88 $77.77 $15.00 $30.00 

XVIII. MULTIPLICATION 

Note. Have pupils notice that the easy way to multiply by 10 is to 
annex a zero to the multiplicand. 

.4. 123945678 
101010101010101010 

B. 10 11 12 15 20 22 30 42 55 
JL0_10J0_1010 10 10 10 10 

XIX. MULTIPLICATION 

Note. Have pupils notice that the easy way to multiply by a multiple 
of 10 is to multiply first by the " significant " figure and then to annex as 
many zeros asy.there are zeros in the multiplier. The zeros in the multi- 
plier may lie to the right of or under the multiplicand. 



A. 14 


14 


10 


10 


10 20 


10 


20 


10 


20 


30 40 


B 32 


32 


2 


2 


2 12 


10 


20 


40 


200 


500 300 

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GRADE IV. FIRST SERIES 69 

XX. PROBLEMS: AT HOME 

(When you read the following numbers be sure that you put and in 
them at the right places.) 

1. Mabel's father paid in house rent in a year |264. He 
paid for his year's supply of coal $90.90. For an auto- 
mobile he paid $795. 

2. In Mabel's home each window has 12 panes of glass. 

Then in 10 windows there are panes. In 20 windows 

there are panes. (Do this second part in two ways.) 

3. How many pounds of coal does Mabel's mother bum 
in her kitchen stove in 10 days if each day she bums 
12 pounds? How much will she bum in the month of 
November? (Do the last part in two ways. Which way 
is the easier?) 

4. Mabel has invited 9 girl friends to a party. She 
wants to have 4 cookies for everyone in the party. How 
many cookies must she have? 

5. She makes 6 bean bags with which to play games. 

Into each bag she puts 200 beans. There will be 

beans in the six bags. 

6. If in Mabel's family 3 pounds of table butter are 

used every week, in 10 weeks the family uses 

pounds. 

7. Mabel's mother preserves eggs in " water glass " in 
5 jars. She puts 30 eggs in each jar. Then she preserves 
eggs in all. 

Additional Work. Each pupil should write out and bring to class 
a similar problem of his own. 

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70 PRACTICE EXERCISES IN MENTAL ARITHMETIC 
XXI. READING NUMBERS 

A. $101.01 $205.50 $100.25 $330.12 

B. $200.10 $510.07 $601.75 $989.90 
a $414.00 $800.86 4716.64 $555.55 

XXII. DIVISION 

Note. When both divisor and dividend end with a zero, teach pupils 
to omit them both (in written work draw a line through them) before 
dividing ; for example, 40 -^ 20 = 4 -s- 2. 

A. lyi lOyiO 10)20 10)30 10)40 

B. 10)110 10)240 20)60 2u)80 20)l20 



a 30)30 30)60 30)90 30)120 50)50 

XXIII. DIVISION 

A. 18-«-9= 180h-90= 80 + 40= 210+30 = 

B. 160 + 80= 270 + 90= 250 + 50= 180 + 60 = 
a 240 + 30= 150 + 30= 220 + 110= 330 + 110 = 
D. 160 + 40= 120 + 60= 240 + 20= 180 + 90 = 

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GRADE IV. FIRST SERIES 71 

XXIV. PROBLEMS: AT HOME 

Note. When you read the following numbers be sure that you use and 
only at the decimal points. 

1. Elsa's father buys a piano for $350, a piano stool 
for $4.50, and a music cabinet for $10.25. His bill for 
the three purchases amounts to $364.75. 

2. Elsa's father is a market gardener. He raised 400 
bushels of potatoes and stored them in bins holding 20 
bushels each. They filled bins. 

3. One day Elsa's father takes to market 120 heads of 
lettuce, which are packed in boxes, 20 heads in a box. 
How many boxes of lettuce does he carry to market? 

4. He has 220 pints of strawberries, which he puts 

into 220 boxes. Each of the boxes must contain 

pints of berries. 

5. Elsa's mother has a piece of cloth that she wishes to 
make into 10 towels. The cloth is 20 yards long. How 
long is the cloth for each towel ? If she wanted to make 
20 towels, how long would she cut each piece ? 

6. The sidewalk in front of Elsa's house is 100 feet long. 
How many boys must be hired to shovel the snow from 
this walk if each boy is paid to shovel 50 feet ? 

7. Elsa's father has 120 pounds of parsnips that he 
wishes to put in boxes holding 20 pounds each. He will 
need boxes. 

Additional Work. Each pupil should write out and bring to class 
a similar problem of his ovm. 

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72 PRACTICE EXERCISES IN MENTAL ARITHMETIC 
XXV. PROBLEMS: MISCELLANEOUS 

1. David lives at No. 708 Park Avenue, and Louise lives 
at No. 819 Park Avenue. Read the numbers correctly. 

2. It is house-cleaning time at David's home. Mother 
plans to have the windows washed. There are 4 panes of 
glass in each window. How many panes are there in 10 
windows? (Do this in two ways, by counting by 4's and 
by multiplying. Which is the easier way?) 

3. David's father buys 17 tons of coal for winter. Of 

this 10 tons is for the furnace, and the rest, tons, 

is for the kitchen stove. 

4. Louise is wiping the dishes for her mother. She 
puts 3 plates on top of a pile of 4 plates, and later she 
puts on the pile 3 more plates. How many are then 
on the pile? 

5. Uncle Henry gave Louise half a pound of chocolate 
creams and her mother a pound of the same kind. Louise 
counted her creams and found that there were 20 of them. 
At the same rate how many creams would her mother 
have ? 

6. There are 24 hours in a day. Children should sleep 
at least 9 hours a day. If they do, how many hours will 
they have left for work and play ? How many hours will 
they have for work and play in 20 days ? 

Additional Work. Each pupil should write out and bring to class 
a similar problem of his own. 

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GRADE IV. FIRST SERIES 78 

XXVI. PROBLEMS: MISCELLANEOUS 

1. The children are playing ** Hide and Seek." Jack is 
" it " and must stand still with his eyes shut while he 
counts by 5's to 100. How quickly can you do this with- 
out making a mistake ? 

2. Hannah's mother usually fries 18 doughnuts on 
Saturday, but company is coming and she thinks she 

should have 28 doughnuts. She will need to fry 

more than usual. 

3. One day in vacation Jack is helping in the hay- 
field. After the hay is all raked up they count 47 
stacks. On the first load 12 stacks are pitched. That 
leaves stacks in the field. 

4. After two loads of hay have been taken from the 

field 22 stacks are left. Then stacks have been 

carried away on the two loads. 

5. The farmer whom Jack is visiting has 20 cords 
of wood that he has planned to sell in the city. He 
expects to carry it in 10 loads of equal size. How 
much will he load on the cart at one time? 

6. This same farmer has 80 pecks of apples that he 
puts into 20 boxes of equal size to carry to market. 

Each box must hold pecks. This is the same as 

bushels. 

Additional Work. Each pupil shotdd write out and bring to class 
a similar problem of his own. 

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GRADE IV. SECOND SERIES 
I. READING NUMBERS 
Note. See Note, p. 60. 

A. 1000 1100 1110 1101 1001 

B. 2105 3060 2400 4075 5000 

C. 3009 1090 4800 4999 2002 

II. ADDITION 

Note. Pupils should look at each combination carefully and give the 
sums from left to right without naming the numbers to be added. 

A. $1.08 $7.05 $9.08 $9.04 $8.20 

.05 5.01 6.01 7.02 6.10 



B. $9.40 
5.10 


$6.20 
3.02 


$6.05 
5.05 


$9.10 
4.01 


$9.70 
3.10 


a $8.00 
7.00 


$5.07 
4.07 


$9.09 
8.09 


$7.08 
4.08 


$8.06 
3.04 



III. ADDITION 

A. $9.70 + 2.02 = $7.04 + 6.30 = $5.03 + 3.10 = 

B. $7.06 + 3.06= $6.40 + 2.40= $5.08 + 2.04 = 

C. $6.10 + 3.30= $8.07 + 2.05= $9.09 + 6.07 = 

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GRADE IV. SECOND SERIES 75 

IV. PROBLEMS: AT SCHOOL 

1. Herbert goes to a large city school in which there are 
40 schoolrooms. In this school 1610 pupils are enrolled. 
There are 3040 pupils in one of the other schools of that 
city. (Be careful about the use of and when you read 
these numbers.) 

2. All the things you use in school cost money. Who 
pays for them ? 

3. In Herbert's school it costs $5.60 to supply all the 
pupils with pencils during the year, and to supply them with 
erasers it costs $1.20. These two articles alone cost . 

4. The desks cost $6.75 each and the seats $3.00 each. 
What do a desk and seat together cost ? 

5. If you lose or destroy a reader costing $0.35 and an 
arithmetic costing $0.40, how much should you pay to the 
teacher ? 

6. It probably costs $8.00 to supply a set of readers 
for your school and $9.00 to supply a set of arithmetics. 
How much will these two sets cost? 

7. If it costs $7.50 to supply your school with paper the 
first half year and $6.40 the second half year, the paper 
you have used during the year costs . 

8. Have pupils find the cost of various articles used in 
school and make original problems in addition. 

Additional Work. Each pupil should write out and bring to class 
a similar problem of his own. 

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76 PRACTICE EXERCISES IN MENTAL ARITHMETIC 
V. READING NUMBERS 

A. LI LII LIV LV LVII LIX LX 

B, LXI LXIII LXX LXXI LXXIV LXXX LXXXI 
a LXXXV XC XCI XCIV XCVI XCIX *C 

VI. ADDITION 

Note. Train pupils to look thoughtfully at each combination before 
they attempt to state the sum. Let them then read the sums from left 
to right. 



A. $10.00 
10.00 


$0.10 

, -10 


$70.00 
30.00 


$0.70 
.30 


$75.00 
25.00 


B. $0.75 
.25 


$50.00 
25.00 


$0.50 
.25 


$5.25 
5.25 


$8.00 
3.00 


a $300.00 

10.000 


$30.00 
10.00 


$3.00 
1.00 


$0.30 
.10 


$0.03 
.01 



VII. ADDITION 
A. $5.00 + 10.00= $32.15 + 32.15= $10.13 + 2.10 = 

5. $60.00 + 40.00= $80.15 + 20.10= $17.30 + 3.03 = 

C. $50.00 + 16.18= $50.00 + 50.00= $33.33 + 66.66 = 

D. $11.22 + 44.33= $61.14 + 17.14= $15.15 + 15.15 = 

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GEADE IV. SECOND SEEIES 77 

VIII. PROBLEMS: AT SCHOOL 

1. Look in your various schoolbooks and state where 
Roman numbers are used. 

2. Peter goes to a two-room school in the country. 
Most of the children are carried to school in automobile 
trucks. One man receives $12.00 a week for carrying the 
children by one route and another receives $15.00 a week 

for carrying them by another route. It costs a week 

to transport these children to and from school. 

3. A wall map of the United States is bought for 
each of the rooms in Peter's school at a cost of $5.10 
each. What do the two maps cost? (Do this in two 
ways. Which is the better way?) 

4. It costs $90.00 for coal to heat Peter's schoolhouse 
in the winter and $10.00 for wood. The expense for heat 
is then a year. 

5. The janitor is paid $300.00 a year to care for the 
school building, and brooms, brushes, and other janitor's 
supplies cost $25.00. It costs to care for the building. 

6. If the expense of repairing damages done to the 
school furniture in Peter's room is $15.00 and to the 
furniture in the other room is $10.00, the furniture- 
repair bill for the year is . 

7. The pupils in Peter's school raised $40.20 by giving 
entertainments and $8.40 by a candy sale. How large 
an amount did the children raise for the school? 

Additional Work. Hack pupil should write out and bring to class 
a similar problem of his own. 

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78 PRACTICE EXERCISES IK MENTAL ARITHMETIC 
IX. COUNTING 

A. Count by 6's to 96. 

B. Count by T's to 98. 

X. SUBTRACTION 
Note. Review pages 86 and 64 before taking this exercise. 



A. $4.10 
2.00 


$4.90 
1.90 


$4.20 
3.10 


$4.80 
2.40 


$5.90 
4.20 


£. $7.00 
3.00 


$4.60 
1.10 


$6.90 
2.30 


$5.50 
3.00 


$5.00 
2.00 


C. $15.50 
2.20 


$0.75 
0.40 


$1.78 
0.75 


$8.50 
0.25 


$55.58 
50.50 



XL SUBTRACTION 

A. $52.00-2.00= $52.00-22.00= $75.00-25.00 = 

B. $1.18-0.18= $17.60-7.40= $30.15-15.15 = 

C. $87.25-11.10= $84.14-24.04= $39.19-35.15 = 
2>. $28.23-28.13= $60.40-50.20= $41.20-20.00 = 
H. $99.99-33.33= $77.77-44.44= $70.85-60.40 = 

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GRADE IV. SECOND SERIES 79 

XII. PROBLEMS: AT SCHOOL 

1. Paul is asked by his teacher to put 7 sheets of 
paper on the front desk of each of the 6 rows in his 
room. How many sheets does he need? (Find this out 
by coimting by 7's and in one other way. Which way 
is easier?) 

2. In Hannah's room the desks are arranged in 7 
rows, with 6 seats in a row. If Hannah puts 6 sheets 
of paper on each front desk for a writing lesson and 

6 sheets for an arithmetic lesson, she will need 

sheets. (Find this by counting and in two other ways. 
Which way do you prefer?) 

3. In Hannah's school the paper used costs $22.50 a 
year. Of this the pupils waste paper to the value of 
$2.50. What is the value of the paper they use? 

4. What is the difference in the cost of a teacher's desk 
bought for $27.33 and a pupil's desk bought for $5.30 ? 

5. When pupils lose pencils to the value of $0.25 
out of a lot costing $6, what is the value of the pencils 
they actually use? 

6. If $84 is paid for coal for your school and only 
$80 worth is used, what value of coal is left over iox 
next year? 

7. In Hannah's school an entertainment is given to 

raise $35. Only $30 is raised, leaving to be raised 

by gifts. 

Additional Work, Each pupil should write out and bring to class 
a similar problem of his own. 

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80 PRACTICE EXERCISES IN MENTAL ARITHMETIC 
XIIL COUNTING 

A. Count by 8's to 96. 

B. Count by 9's to 99. 

XIV. MULTIPLICATION 
Note. Review pages 52, 66, and 68 before taking this exercise. 



A. $9 
2 


$0.09 
2 


$6 
3 


$0.06 
3 


$6 
4 


$0.06 
4 


B. $12 
2 


$0.12 
2 


$11 

7 


$0.11 

7 


$10 
6 


$0.10 
6 


a $8 
3 


$0.12 
6 


$0.07 
7 


$7 
4 


$11 
6 


$0.08 
6 





XV. MULTIPLICATION 

A. $12.00x9= $8.00x8= $12.00x5= $9.00x8 = 

B. $0.09x5= $0.08x6= $0.08x7= $0.09x4 = 
a $1.11x2= $3.30x3= $15.00x2= $15.15x2 = 
2). $50.00x2= $25.25x3= $30.20x3= $10.11x4 = 
K $14.14x2= $9.09x5= $8.08x6= $9.10x9 = 

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GRADE IV. SECOND SERIES 81 

XVI. PROBLEMS: AT SCHOOL 

1. If a pad of paper costs $0.06 and there are 9 
pupils in a class, how much does it cost to supply the 
class with pads? 

2. There are 9 sets of books, in each of which there 
are 8 books that need rebinding at the end of the 

year. In all the sets there are books that need 

rebinding. (Do this by counting and in one other way. 
Which is the better way?) 

3. What is the cost of putting new covers on 8 books 
at $0.11 a book? 

4. The janitor puts a new box of crayons in each 
schoolroom at the beginning of the year. How much 
does it cost to supply a two-room building at $0.20 a box ? 
(Do this last part in two ways. Which is the easier ?) 

5. It costs $0.25 to replace a broken pane of glass. 
How much should boys pay who break 3 panes? 

6. Paul has carelessly scratched his desk. It costs 
$1.10 to repair the damage. If there are 5 careless 
children in school who damage their desks as Paul did, 
how much of the taxpayers' money have they wasted? 

7. If it costs $7 to' buy a set of readers for your 
class, how much will it cost to supply 6 classes at the 
same price? 

8. John's pencils cost $0.06 each. If he loses 4 of 
them in a year, how much money has he wasted? 

Additional Work. Each pupil shovld write out and bring to class 
a similar problem of his own. 

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82 PRACTICE EXERCISES IN MENTAL ARITHMETIC 
XVII. COUNTING 

A. Count by ll's to 99. 

B. Count by 12's to 96. 

XVIII. MULTIPLICATION 



A. $9 
12 


$8 
8 


$0.05 
12 


$0.08 
9 


$0.05 
9 


$0.06 
8 


B. $4.00 
9 


$7.00 

7 


$8.00 
8 


$6.00 
6 


$5.05 
8 


$6.06 
9 


a $7 
10 


$7 
20 


$7 
30 


$8 
40 


$9 

ioo 


$10 
10 


D. $7.07 
9 


$4.04 
8 


$6.06 
11 


$4 
70 


$11 
11 


$22 
40 



XIX. MULTIPLICATION 

A. $12x12= $11x30= $0.12x6= $0.03x7 = 

B. $0.02x8= $2.02x6= $4.04x8= $9x3 = 

C. $9.09x11= $60x10= $6x50= $8.08x11 = 
2>. $9.09x9= $12x50= $11x80= $10x20 = 
K $12x9= $12x5= $0.09x8= $0.09x5 = 

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GRADE IV. SECOND SERIES 88 

XX. PROBLEMS: AT SCHOOL 

1. How many ll's do you count if you start with 11 
and count to 99 ? Which is easier, to count by ll's to 
99 or to multiply 11 by 9? Try it before you answer. 

2. How many pencils are there in a bundle contain- 
ing a dozen? The teacher sends Charlotte to the supply 
room to get 8 dozen pencils. Count them for her as 
she takes each package and state the number of pencils 
she will have. 

3. The school board has decided to put new seats 
and desks in Charlotte's room. There is room for 40 
pupils, and the seats and desks together cost $8 each. 
The new seats and desks cost . 

4. New window shades also are put up in Charlotte's 
room. There are 5 windows, and each shade costs $0.20. 
It costs to supply the shades. 

5. The janitress is paid $1 a day to take care of the 
little country school that Charlotte attends. A school 

week for the janitress is 6 days. She receives a 

week. For a fortnight she receives . Her pay for 

a month is . (Do this last part in three ways and 

select the easiest way.) 

6. Charlotte's teacher is paid $90 a month. How 
much is that for a school year of 10 months? 

7. If the teacher pays $10 a week for board during 
the school year of 40 weeks, she will pay . 

Additional Work. Each pupil should vrrite out and bring to class 
a similar problem of his ovm. 

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84 PRACTICE EXERCISES IN MENTAL ARITHMETIC 
XXL READING FRACTIONS 

^. i f I I I i f t i 

XXIL DIVISION 

Note. In this exercise the divisors are abstract. The division separates 
the dividend into parts ; that is, the quotient is a certain part (represented 
by the divisor) of the dividend. Review pages 40, 54, and 70. 



A, 2)|2 5)$5 2)$0.02 3)$0.03 3)$3 



B, 10)$10 lOjIoIO 2)$al0 20)$20 20)|0^ 
a 9)$0.18 7)$0.49 8)$8.08 5)$25.10 6)$12.30 

XXIIL DIVISION 

Note. In this exercise the divisors are the same kind as the dividends. 
The quotients are therefore abstract, representing the number of times that 
the divisor is contained in the dividend. 

A. $2)f2 $5)|5 $6)|60 $12)$72 $0.02)$0:02 

B. $11)199 $0.11)1099 $9)$36 $20)$40 $30)$60 
a $0.10)$0;20 $10)$20 $5)|50 $0.05)$0^ 

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GRADE IV. SECOND SERIES 85 

XXIV. PROBLEMS: AT SCHOOL 

1. Half a dozen pointers have been bought for use 
at the blackboard in your school at a cost of $0.60. 
If you break one, how much ought you to pay for it? 

2. It may cost $0.75 to put curtains at the three 
windows of your schoolroom. If one is broken, how 
much will it cost to replace it? 

3. The pencils like those that Paul uses in school cost 
$0.06 at the store. How many can he buy with $0.06? 

4. Paul has $0.18 with which he wants to buy as 
many pencils hke those he uses in school as he can. 

He can buy pencils with his $0.18. (Do this by 

counting and in one other way. Which way is easier?) 

5. $0.99 is paid for blackboard erasers. If each one 
costs $0.11, how many are bought ? (In what two ways 
can you do this? Which is easier?) 

6. If in a four-room building the pupils could save 
for the taxpayers $16 by avoiding waste, what would 
the share of saving be for each room? How could the 
pupils avoid waste? What would the money saved buy 
that would be useful in your school? 

7. At the close of the school year 6 desks in Paul's 
room are so badly scratched that they are refinished at 
a cost of $6.60. How much has each of the six careless 
children cost the taxpayers? 

Additional Work. Each pupil should write out and bring to class 
a similar problem of his ovm. 

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86 PRACTICE EXERCISES IN MENTAL ARITHMETIC 
XXV. PROBLEMS: MISCELLANEOUS 

1. In Jane's and Harry's school it was decided to 
hold a Christmas sale. At Jane's table $9.30 was re- 
ceived from the sale of candy, and at Harry's table 
$7.20 was received from the sale of toys. At both tables 
was received. 

2. Anna was at the head of the table where boys' neck- 
ties were sold. She sold 9 of them at $0.11 each, receiving 
in all for the neckties. 

3. Some of the boys fixed up a side show. $0.05 was 
charged for entrance tickets. Stephen, who was door- 
keeper, found that he had taken in 15 nickels. By count- 
ing by 5's he found that he had received cents in 

nickels. Could he have found out more quickly in some 
other way than by counting ? 

4. Susan sold 20 Christmas cards for which she received 
$0.40. If they were all sold at the same price, what was 
charged for each one ? 

5. The Christmas cards that were sold for $0.40 were 
purchased at a friendly stationer's for $0.20. So the profit 
that went into the school funds was . 

6. When the Christmas sale was over, all the money 
received was counted. It was found that $25.00 had been 
taken in at tables and side shows and $10.25 had been 
taken by the sale of admission tickets. In all that 
made . 

Additional Work. Each pvpil shcndd tmte out and bring to class 
a similar problem of his oum. 

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GRADE IV. SECOND SERIES 87 

XXVI. PROBLEMS : MISCELLANEOUS 

1. Ink is often bought for schools by the gallon. If 
$0.80 is paid for a gallon, how much does it cost to fill 
a quart bottle for Roland's room ? 

2. Paper is bought by the school committee in 
packages containing 500 sheets. In 5 packages there 
are sheets. 

3. Viola is asked by her teacher to give 2 sheets of 
paper to each of the 42 pupils in her room. Find out 
by coimting by 2's how many sheets she needs. Find 
out in an easier way than by counting. 

4. If $0.23 is paid for each package of paper in a 
school, how much has it cost the taxpayers to supply 
your room with 3 packages? 

5. Suppose that in one month the pupils in your school 
could save $1.00 by being careful in the use of supplies. 
At the end of the school year of 10 months they will 
have saved . 

6. In Harold's school it is decided to buy some play- 
ground apparatus. The cost is looked up, and it is found 
that a football costs $3.10 and that a basket ball costs the 
same. If one of each is bought the school must raise . 

7. For baseball 2 bats are needed costing $0.25 each 
and a ball costing $0.50. How much more must be raised 
if the school decides to play baseball? 

Additional Work. Each pupil should write out and bring to class 
a similar problem of his own. 

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GRADE IV. THIRD SERIES 
I. READING MIXED NUMBERS 

Note. When reading mixed numbers the word and should be used only 
between the whole number and the fraction. 101^ is read ''one huudred 
one and one half." See Note, p. 66. 



A. li 


^ 


H 


H 


H 


6| 


7| 


B. 9f 


10| 


15| 


18| 


20i 


50| 


98i 



II. FRACTIONAL PARTS 

^. ^ of 1 = I of 2 = i of 4 = i of 10 = 

5. ^ of 1 = i of 3 = i of 6 = ^ of 12 = 

C. J of 1 = -1- of 4 = i of 8 = J of 16 = 

D. ^ oi 9= I of 14 = J of 12 = ^ of 15 = 

III. FRACTIONAL PARTS 

^. J of 20 = i of 24 = J of 28 = J of 36 = 

A i of 24 = i of 30 = ^ of 36 = ^ of 60 = 

C. J of 40 = ^ of 50 = i of 80 = ^ of 100 = 

D. ^ of 60 = ^ of 75 = J of 88 = J of 100 = 

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GRADE IV. THIRD SERIES 89 

IV. PROBLEMS: AT THE NEWSDEALER'S STORE 

1. Harold is a newsboy who buys his papers of 
Mr. Carlton at No. 7014 Main Street. Harold pays 1^^ 
for some papers and IJ^ for others. He wears a badge 
that has the number 82 on it.. Read the numbers 
correctly. 

2. One day Harold bought 30 papers, but only sold 
^ of them. Then he sold papers. 

3. Mr. Carlton put 3 dozen bottles of ink on his 
shelf and sold J of them in a week. How many ink 
bottles did he sell in a week? 

4. If there are 4 jars of candy on the shelf and J 
is broken, there are jars remaining on the sheK. 

5. Mr. Carlton buys 100 papers every night, but 
sells only ^ of them in the store, selling the rest through 

newsboys. Then he sells papers in the store, and 

the newsboys sell papers. 

6. If Mr. Carlton tells Harold to put the 4 dozen 
magazines on 4 shelves, an equal number on each shelf, 

he should put magazines on each shelf. (The 

answer may be given in two ways.) 

7. Every week Harold sells 22 Saturday Evening 
Posts. . Of these he delivers ^ at the homes of regular 
subscribers and the rest he sells on the street. Then 
he has regular customers. 

Additional Work. Each pupil should write out and bring to class 
a similar problem of his otvn. 

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90 PRACTICE EXERCISES IN MENTAL ARITHMETIC 

V. COUNTING BY FRACTIONS 

Note. This and similar exercises will familiarize pupils with the names, 
sequence, and relative value of fractions. The pupils will say, " ^, | or 1 ; 
f, J or 2; "etc. 

A. Count by halves to 10. 

B. Count by thirds to 10. 

VI. MEASURES OF LENGTH 
A. 1 ft. = ? in. 2 ft. = ? in. 3 ft. = ? in. 

5. J ft. = ? in. ^ ft. = ? in. ^ ft. = ? in. 

a 1yd. =? ft. 2 yd. = ?ft. 5 yd. =?ft. 

D. 1 yd. = ? in. ^ yd. = ? in. J yd. = ? in. 

K 1^ ft. = ? in. 11 ft. = ? in. IJ ft. = ? in. 

VIL MEASURES OF LENGTH 

A. 12 in. = ? ft. 18 in. = ? ft. 24 in. = ? ft. 

B. 3 ft. = ? yd. 6 ft. = ? yd. 9 ft. = ? yd. 

C. 36in. = ?yd. 18in. = ?yd. 9in. =?yd. 

D. 24 in. = ? ft. 36 in. = ? ft. 18 in. = ? ft. 
K ? in. = ^ yd. ? ft. = ^ yd. ? in. = i yd. 

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GRADE IV. THIRD SERIES 91 

VIII. PROBLEMS: AT THE DRY-GOODS STORE 

1. The clerk behind the ribbon counter is cutting a 
long piece of ribbon in half-yard lengths. After she 

has cut 8 such lengths, she has used yards of 

ribbon. (Find the number of yards by counting by 
half-yards.) 

2. If the clerk cut the ribbon into 12-inch lengths, 
how many yards would she use in cutting 3 lengths? 
(Find this answer in three ways and choose the easiest 
way.) 

3. The clerk at another counter sells IJ yards of 
silk. How many inches more than a yard is that? 

4. A tape measure is generally 60 inches long. One half 
of it is how many inches long? 

5. A piece of cloth is 24 inches in width. How 
many feet wide is it? 

6. If a piece of cloth is J yard wide, how many 
inches wide is it? 

7. If a boy wears a 13-inch collar, what will it 
measure in feet and inches? 

8. Anna buys enough ribbon to make a bow 2 feet 
long. How many inches does the clerk measure off? 
How many inches less than a yard does Anna buy? 
What part of a yard is left? 

Additional Work. Each pupil should write out and bring to class 
a similar problem of his own. 

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92 PRACTICE EXERCISES IN MENTAL ARITHMETIC 
IX. COUNTING BY FRACTIONS 

A. Count by fourths to 10. 

B. Count by fifths to 10. 

X. MEASURES OF AREA 

A. 1 sq. ft. = ? sq. in. 2 sq. ft. = ? sq. in. 

B. 1 sq. ft. = ? sq. in. J sq. ft. = ? sq. in. 
a 1 sq. yd. = ? sq. ft. 2 sq. yd. = ? sq. ft. 
D, 3 sq. yd. = ? sq. ft. 5 sq. yd. = ? sq. ft. 
K 10 sq. yd. = ? sq. ft. 20 sq. yd. = ? sq. ft. 

XL MEASURES OF AREA 

A, 144 sq. in. = ? sq. ft. 288 sq. in. = ? sq. ft. 

B, 72 sq. in. = ? sq. ft. 36 sq. in. = ? sq. ft. 
a 9 sq. ft. = ? sq. yd. 18 sq. ft. = ? sq. yd. 
D. 36 sq. ft. = ? sq. yd. 90 sq. ft. = ? sq. yd. 

U. How many inches around (perimeter) 1 sq. in.? 

F, How many feet around 1 sq. ft.? 

G. How many yards around 1 sq. yd.? 
H. How many feet around 1 sq. yd.? 

I. How many inches aroimd 1 sq. ft.? 

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GRADE IV. THIRD SERIES 98 

XII. PROBLEMS : AT A HARDWARE STORE 

1. The hardware dealer sells and uses foot-rule measures. 
Take your ruler and count by fourth (or quarter) inches to 
the 3-inch division line. How many quarter inches are 
there? What is an easier way of finding the niunber of 
quarter inches in 3 inches? 

2. Stephen goes to the hardware store and asks for 
a square yard of mosquito netting. How many yards long 
will it be ? How many yards wide ? 

3. If the dealer uses a foot rule to measure the netting 
for Stephen, how many feet will he measure oflE for the 
length and the width? 

4. How many square feet will Stephen's netting contain ? 

5. What is the perimeter of Stephen's netting in yards ? 
in feet ? (Find the perimeter in two ways. Which is the 
easier way ?) 

6. One day Stephen breaks a pane of window glass. He 
measures the old glass and finds that it measures 12 inches 
in length and 12 inches in width. He must pay for the 
area of glass he needs. How many square inches must he 
buy ? This is how many square feet ? 

7. Stephen must also buy putty to fasten the glass in 
place. How many inches in length must he apply the 
putty? How many feet? 

Additional Work, Each pupil shovJd write out and bring to class 
a similar problem of Ms own. 

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94 PRACTICE EXEBCISES IN MENTAL ARITHMETIC 

XIII. MEASURES OF SOLIDS 

A. 1 cu. ft. = ? cu. in. 1 cu. yd. = ? cu. ft. 

B. How long is a cu. ft.? a cu. yd.? 

C. How wide is a cu. ft.? a cu. yd.? 

D. How high is a cu. ft.? a cu. yd.? 

XIV. MEASURES OF LIQUID 

A. 1 pt. = ? gi. 2 pt. = ? gi. 3 pt. = ? gi. 

B. 4 pt. = ? gi. 1 qt. = ? pt. 2 qt. = ? pt. 

C. 1 gal. = ? qt. 2 gal. = ? qt. 10 gal. = ? qt. 

D. 2 gi. = ? pt. 1 gi. = ? pt. 3 gi. = ? pt. 

E. 2 pt. = ? qt. 1 pt. = ? qt. 3 pt. = ? qt. 

F. 4 pt. = ? qt. 4 qt. = ? gal. 1 qt. = ? gal. 

XV. MEASURES OF DRY SUBSTANCES 

A. 2 pt. = ? qt. 4 pt. = ? qt. 3 pt. = ? qt. 

B. 8 qt. = ? pk. 4 qt. = ? pk. 16 qt. = ? pk. 

C. 4 pk. = ? bu. 8 pk. = ? bu. 2 pk. = ? bu. 

D. ^ bu. = ? qt. ^ bu. = ? pk. i pk. = ? qt. 
K l|bu. = ?pk. lipk. = ?qt. 3pk. = ?qt. 
F. 2bu. = ?pk. 2bu. = ?qt. 10bu. = ?pk. 

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GRADE IV. THIRD SERIES 96 

XVL PROBLEMS: AT THE PROVISION STORE 

1. In Mr. Harper's provision store there is a big 
block of wood on which he chops his meat. It meas- 
ures 3 feet across one way, 3 feet across the other way, 
and is 3 feet thick. How large would you say this 
block is? (The answer may be given in two ways.) 

2. On a shelf that is 12 inches wide Mr. Harper 
wants to put a box that he finds measures a cubic foot. 
How far apart must the shelves be and how much 
space on the shelf will the box take? 

3. Mr. Harper buys a bushel of green peas from a 
farmer, but he sells them by the quart. How many 
quarts can he sell from the bushel? 

4. A barrel of apples is 2^ bushels. How many pecks 
should Mr. Harper be able to sell out of the barrel? 

5. Vinegar is bought by Mr. Harper in a keg holding 
10 gallons. If his customers buy vinegar by the quart, 
he can draw off quarts from his keg. 

6. Mr. Harper has 20 customers that buy a quart of 
milk a day in glass jars. How many gallons of milk 
does that amount to? 

7. Out of a box containing a bushel of potatoes 

Mr. Harper sells a peck. Then pecks remain in 

the box. 

AdHtianal Work. Each pupil should write out and bring to class 
a similar problem of his own. 

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96 PRACTICE EXERCISES IN MENTAL ARITHMETIC 

XVIL MEASURES OF WEIGHT 
A. llb. = ?oz. Jlb. = ?oz. ^lb. = ?oz. 

5. 1 T. = ? lb. ^ T. = ? lb. 2 T. = ? lb. 



a 16oz. = ?lb. 
D. 2000 lb. = ? T. 



8 oz. = ? lb. 
1000 lb. = ? T. 



4 oz. = ? lb. 
30001b. = ?T. 



XVIII. MEASURES OF TIME 
A. 1 min. = ? sec. ^ min. = ? sec. J min. = ? sec. 

^ hr. = ? min. ^ hr. = ? min. 

1 da. = ? hr. 2 da. = ? hr. 

1 wk. = ? da. 2 wk. = ? da. 

1 yr. = ? wk. 1 yr. = ? mo. 



B. 1 hr, = ? min. 

C. 1^ hr. = ? min. 

D. ^ da. = ? hr. 
K 1 yr. = ? da. 



XIX. MEASURES OF TIME 
A. 60 sec. = ? min. 30 sec. = ? min. 15 sec. = ? min. 

90min. =?hr. 
24 hr. = ? da. 
7 da. = ? wk. 
6 mo. = ? yr. 



B. 60min. = ?hr, 

C. 15 min. = ? hr 

D. 48hr. = ?da. 
H. 365da. = ?yr. 



30 min. = ? hr. 
12 hr. = ? da. 
4 wk. = ? mo. 
52 wk. = ? yr. 

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GRADE IV. THIRD SERIES 97 

XX. PROBLEMS: AT THE BAKESHOP 

1. Anna buys a large loaf of bread (1-pound loaf) at 
the baker's. How many ounces of bread does she buy? 

2. The baker buys a ton of flour. If he bakes it 
into bread, putting a pound of flour into each loaf, he 
will bake loaves. 

3. If the baker makes another ton of flour into loaves 

containing half as much flour, he will make small 

loaves. 

4. Each kind of food the baker makes requires a 
particular length of time for baking. If it takes f hour 
to bake bread, how many minutes does it require? 

5. But to make good bread it must be *' raised." 
This requires about ^ day, or hours. 

6. One man has worked for Mr. Harris, the baker, 
a whole year without one day off. How many days 
has he worked? 

7. If a man takes 1 day off each week, he works 
days in the year. 



8. A working day is one third of a whole day. How 
many hoiKS a day does a man work? 

9. If the clerk in the bakeshop has | hour for lunch 
at noon, he is away from the store minutes. 

Additional Work. Each pupil should write out and bring to class 
a similar problem of his own. 

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PRACTICE EXERCISES IN MENTAL ARITHMETIC 

XXI. COUNTING 
2 doz. = ? units 
J doz. = ? units 
1 gro. = ? units 

18 units = ? doz. 
24 units = ? doz. 
144 units = ? gro, 



A. 1 doz. = ? units 

B, ^ doz. = ? units 
C 1 gro. = ? doz. 

D. 12 units = ? doz 

E. 4 units = ? doz. 

F. 12 doz. = ? gro. 



3 doz. = ? units 
^ doz. = ? units 
\ gro. = ? doz. 

6 units = ? doz. 
3 units = ? doz. 
6 doz. = ? gro. 



XXII. MEASURES OF PAPER 

A, 1 quire = ? sheets ^ quire = ? sheets \ quire = ? sheets 

B. 1 ream = ? sheets 2 reams = ? sheets ^ ream = ? sheets 

C. 24 sheets = ? quires 6 sheets = ? quires 

36 sheets = ? quires 

D, 500 sheets = ? reams 250 sheets = ? reams 

1000 sheets = ? reams 

XXIII. MEASURES OF UNITED STATES MONEY 
A, 1 ct. = ? mills 2 ct. = ? mills ^ ct. = ? mills 

5d.= ?^ 
$1.00 = ? ^ 
$1.00 = ? d. 



B. 1 d. = ? ^ 

C. 10 d. = ? ct. 

D. $i=?^ 

E. 10 mills = ? ct. 

F. 5^=?d. 



5 mills = ? ct. 
100^ = ? $ 



8d. = ?^ 
$i = ? ct. 
$i = ?d. 

10^ = ?d. 
50^ = ? $ ? d. 

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GRADE IV. THIRD SERIES 99 

XXIV. PROBLEMS : AT THE STATIONERY STORE 

1. Mr. Morris keeps a stationery store. He buys pencils 
by the gross. If he buys two gross of Faber's pencils, how 
many pencils does he buy ? How many dozen pencils ? 

2. Arthur buys half a dozen pencils. Mr. Morris counts 
out pencils from a package containing 1 dozen. 

3. If Mr. Morris buys 1 gross of small ink bottles and sells 
6 dozen of them, he has dozen left, or bottles. 

4. Mr. Morris opens a package of paper containing a 

ream and sells half of it. He should have sheets 

remaining in the package. 

5. A customer buys 2 quires of paper. How many 
envelopes will he need if he plans to put only one 
sheet in each envelope? (Envelopes generally are sold 
in packages. How many are there in a package?) 

6. Arthur gives Mr. Morris a dime when he buys a 
5^ pencil. He should receive ^ in change. 

7. If Mr. Morris sells 10 paper napkins for 1^, each 
costs mills. You can buy napkins for a dime. 

8. Arthur receives 5 dimes as change one day when 
he buys some stationery for his mother. How many 
cents might Mr. Morris have given him? 

9. If Arthur had received his change, amounting to 
5 dimes, in one piece of money, he would have received 
dollar. 

Additional Work, Each pupil should write out and bring to class 
a similar problem of his owru 

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100 PRACTICE EXERCISES IN MENTAL ARITHMETIC 
XXV. PROBLEMS: MISCELLANEOUS 

1. Alan went to the grocery store and bought -|- dozen 
eggs and ^ pound of butter. How many eggs did the 
grocer count out for him and how many ounces of butter 
did he weigh out on the scales ? 

2. The fruit man sells 2 apples for 1^. That is at the 
rate of one apple for ^, or mills. 

3. If you buy 2 reams of paper how many sheets will 
you buy ? 

4. The owner of a candy store buys of the wholesale dealer 
a box of candy containing 100 pieces. The pieces are packed 
in 5 layers. There must then be pieces in each layer. 

5. Mother asks Gertrude to take the tape measure and 
measure off 2 yards of a piece of cotton cloth that she 
has bought. How many inches does she measure off ? 

6. Chester is sent to the hardware store to buy a piece of 
2inc to put under his mother's stove. It is to be a square 
yard in size. What will it measure on the four sides ? 

7. Suppose you are a clerk in a bakeshop. Count out 
3 dozen doughnuts by 2's ; by 3's ; by 4's. 

8. Chester buys at the hardware store 5 screws for 1^. 
That is at the rate of 1 screw for mills. 

9. Chester pays 20^ for some ribbon for his sister and 
gives the clerk $1.00. His change is all in dimes. How 
many does he receive ? 

Additional Work. Each pupil should write out and bring to class 
a similar problem of his own. 

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GRADE IV. THIRD SERIES 101 

XXVI. PROBLEMS: MISCELLANEOUS 

1. Viola goes to the grocery store and buys cream in 
a small bottle holding one-half pint. How many gills 
of cream does she buy? 

2. The grocer has in his refrigerator 20 pint bottles 
of milk. How many quarts does that make? 

3. If he has 2 gallons of milk in a can, he can sell 
from it quarts. 

4. The provision dealer has a box containing a bushel 

of potatoes. He sells Arthur a peck. He has pecks 

left in the box. How many quarts of potatoes are left? 
(Do this in two ways and decide which is the easier way.) 

5. The provision dealer has an ice box that measures 
inside 3 feet in length, 3 feet in width, and 3 feet in 
depth. How many cubic yards of ice will it contain? 
How many cubic feet of ice? 

6. Mr. Harris, the market man, has 500 pounds of 
ice put in his refrigerator every week. In how many 
weeks does he use 1 ton of ice? 

7. Viola happened to be in a jeweler's shop when the 
jeweler was setting a watch that was a Kttle slow. He 
sets it forward one-half minute, or seconds. 

8. The clerk in the bakeshop has a two weeks' vaca- 
tion in summer. That is month, or days. 

9. If John, the provision clerk, works 10 hours a 
day, that leaves him hours for himself. 

Additional Work. Each pupil should write out and bring to class 
a similar problem of his own. 

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GRADE IV. FOURTH SERIES 
I. TWO PEOCESSES 

A, 2 + 4-1= 18-10 + 9= 16-9 + 7= 6 + 9-7 = 

B, 18-8 + 7= 5 + 8-6= 15-7 + 6= 13-7 + 7 = 

II. ADDITION 

Note. Have pupils note the numbers that in sequence make 10 before 
they begin to add. This should become a habit in all addition. Encourage 
adding other combinations also ; that is, 3 + 1, 2 + 1, 2 + 2, 3 + 2, etc. 



A. 5 


7 


9 


3 


2 


3 


3 


2 


5 


3 





3 


7 


7 


4 


■ 4 8 





1 


1 


3 


1 


5 


3 


4 


5 





6 


1 


5 


5 


1 


2 5 


B. 6 


6 


1 


2 


7 


7 


1 


5 5 


3 


3 


7 


5 


8 


4 


3 


2 4 


1 


1 


3 


5 


2 


6 


7 


8 1 





8 


4 


3 


7 


3 


3 


2 7 








III. 


ADDITION 






A. 2 


7 


9 


2 


5 


7 


6 


5 4 


8 


3 


5 


3 


7 


1 


2 


1 4 


3 


6 


3 


8 


3 


1 


1 


2 2 


9 


4 


2 


2 


5 


1 


1 


2 2 


B. 3 


6 


1 


2 


2 


5 


6 


7 9 


3 


4 


9 


■ 2 


7 





6 


8 6 


7 


6 


7 


2 


1 


8 


6 


5 7 


3 


8 


2 


4 


4 


2 


4 

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5 3 

Google 



GRADE IV. FOURTH SERIES 108 

IV. PROBLEMS OF THE CONDUCTOR 

1. The conductor on a street car or a railroad train is 
obliged to do a great many examples. In one freight train 
there are 3 box cars, 4 platform cars, 6 tank cars, and 1 
caboose. The conductor reports cars in his train. 

2. Hilda rode from New York to Chicago in a train 
consisting of (besides the engine) 1 baggage car, 1 smok^ 
ing car, 4 parlor cars, and 6 coaches. The engine drew 
cars in this train. 

3. Nelson was riding on a train that made four stops. 
How many people got off if 8 people stopped at the 
first station, 2 at the second, none at the third, and 5 
at the fourth? 

4. At one stop a number of people get on a street car. 
After the car has started, the conductor finds that he 
has received 4 tickets, 3 cash fares, 3 transfers, besides 
7 passes from policemen and others who ride without 
paying fares. Then people got on at that stop. 

5. A motorman makes 4 trips a day, each trip taking 
3 hours. How long does he work each day? (Do this 
in two ways, selecting the easier way.) 

6. A conductor is obliged to stop his train four times 
during one trip. At the first stop he loses 3 minutes, 
at the second 7 minutes, at the third 7 minutes, and 
at the fourth 3 minutes. How late is his train at the 
end of the trip? 

Additional Work. Each pupil should write out and bring to class 
a similar problem of his own. 

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104 PRACTICE EXERCISES IN MENTAL ARITHMETIC 

V. TWO PROCESSES 

A. 3 + 9-5= 17-8 + 9= 15-7 + 3= 16-8 + 8 = 

B. 4 + 8-7= 15-8 + 3= 21-7-7= 4 + 6 + 10 = 
a 12-7 + 6= 11-8 + 5= 14-2 + 7= 7 + 7 + 2 = 









VI. 


ADDITION 








A. 2 


5 


7 


8 


4 


6 


7 


2 


3 


7 


3 


1 


2 


5 


3 


2 





4 


1 


2 





6 





4 


7 


5 


3 


4 


6 


9 


4 


5 


6 


3 


6 


7 


3 


4 


1 





5 


3 


4 


4 





B. 4 


3 


2 


5 


6 


8 


7 


3 


2 


4 


6 


3 


7 





1 


2 


3 


2 


2 


4 


3 


3 


1 


1 


1 


3 


3 


8 





2 


8 


8 


4 


1 


1 


3 


7 


5 


5 


2 


2 


5 


4 


3 


9 








VII. 


ADDITION 








A. 4 


5 


9 


6 





5 


7 


2 


5 


6 





1 


4 


3 


2 





6 


2 


4 


8 


5 


4 


7 


8 


7 


2 


6 


5 


1 


5 





1 


5 


3 





4 


5 


1 





6 


9 


5 


7 


7 





B. 8 


7 


2 


1 


4 


3 


9 


6 


5 


9 


9 


3 


1 


6 


7 


6 


3 





2 


4 


1 


1 


9 


8 


4 


7 


7 


8 


6 


4 


2 


3 


5 


6 





7 


7 


8 


6 


8 


7 


5 


4 


8 


3 












1 


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GRADE IV. FOURTH SERIES 106 

VIII. PROBLEMS OF THE POST OFFICE 

1. If Mr. Casey, the letter carrier, has a bundle con- 
taining 14 letters and delivers 2 letters at one house 

and 2 at another, he has letters left to deliver. 

(Do this in two ways and select the easier way.) 

2. The postmaster has in his stamp drawer 21 two-cent 
stamps. He sells 11 of them, but later puts 5 more in 
the drawer. There are then in the drawer two- 
cent stamps. 

3. Five people buy two-cent stamps at the post 
office. How many have they bought when the first 
has purchased 5 stamps, the second 5, the third 2, the 
fourth 3, and the fifth 5? 

4. At different times during the day mail bags come 
to the office with letters and papers from different parts 
of this country. If 4, 4, 2, 7, and 3 bags are brought at 
different times during the day, the office receives in all 
bags. 

5. On one trip the letter carrier delivered 3 parcel- 
post packages at one house, 1 package at another, and 3 
packages to each of three other places. In all he deliv- 
ered on that trip parcel-post packages. (Do this 

in two ways and select the easier way.) 

6. In a large city there are five branch post offices. 
There are 5, 5, 6, 3, and 7 carriers connected with the 
several offices. This city has letter carriers. 

Additional Work. Each pupil should write out and bring to class 
a similar problem of his own. 

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106 PRACTICE EXERCISES IN MENTAL ARITHMETIC 

IX. TWO PROCESSES 

Note. In this and all similar exercises have pupils perform the multi- 
plication and division processes before the addition and subtraction ; other- 
wise perform the operations in the order of their occurrence. 

A. 6-^2 + l= 8-^2 + 2= 8 + 2-5-2= 4 + 9-i-3 = 

B. 12h-4-2= 70^10-5= 18-8^2= 24-7^7 = 
a 254-6^3= 27"9-f-3= 15^5-h3= 27-9-2 = 

X. MAKING CHANGE 

Note. Pupils should make change as storekeepers do, by adding to the 
amount of the purchase enough to equal the amount given by the pur- 
chaser. That is, if $0.25 is given for a $0.03 purchase, the storekeeper 
will say, "$0.03 and $0.02 are $0.05; $0.05 and $0.10 are $0.15, and 
$0.10 are $0.25." 

Pupils should be given freedom to make any practical combinations. 

In the following the lower number represents amount of sale : 

A. $0.10 $0.25 $0.20 $0.35 $0.30 $0.50 $0.50 

0.02 0.17 0.16 0.26 0.21 0.30 $0.12. 

B. $0.25 $0.25 $0.25 $0.45 $0.45 $0.35 $0.25 

0.08 0.18 0.06 0.37 0.39 0.29 0.12 

XL MAKING CHANGE 



1. $0.50 
0.25 


$0.60 
0.51 


$0.75 
0.50 


$0.85 
0.79 


$0.90 $0.95 $1.00 
0.81 0.86 0.50 


(, $0.50 
0.17 


$0.50 
0.28 


$0.75 
0.60 


$0.70 
0.61 


$0.50 $0.65 $1.00 
0.35 0.58 0.65 

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GEADE IV. FOURTH SERIES 107 

XII. PROBLEMS OF THE FRUIT SELLER 

1. Mr. Rossi keeps a fruit stand. In a box there are 
25 oranges. He puts 5 more with them and then divides 
them into three equal lots of oranges each. 

2. If the fruit dealer has 24 boxes of grapes, sells 4 
boxes, and divides the rest into two lots, one of which 
he puts in a dark room, how many boxes does he leave 
on sale? 

3. Clara buys a banana for $0.02 and gives $0.10 in 
payment. Find her change. 

4. What change does Mr. Rossi return to Tony, who 
gives him $0.25 for a $0.03 orange? 

5. A customer buys a dozen lemons costing $0.36. Count 
out his change for $1.00. 

6. If $0.50 is given in payment for grapes costing $0.15, 
what is the change ? 

7. Rosa buys of Mr. Rossi a pound of dates for $0.12. 
What change does she receive if she gives him $0.20 ? 

8. What change does Mr. Rossi give a customer who 
gives him $0.75 for fruit costing $0.52? 

9. Mr. Rossi has 90 grapefruit that he arranges in his 
show window in three piles of equal size. He sells 6 grape- 
fruit from one pile. How many are left in that pile ? 

Additional Work. Each pupil sfwidd write out and bring to class 
a similar problem of his own. 

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108 PRACTICE EXERCISES IN MENTAL ARITHMETIC 

XIII. TWO PROCESSES 

A. 3 + 2x2= 4-1x3= 4x10-5= 8h-4x6 = 

B. 7-8-s-2= 4-5-4x6= 12-1-4 + 2= 5x5 + 2 = 

C. 6^3-8-2= 3x4x2= 39-i-13-2= 16-4-5-4 = 

D. 8x5-5-4= 42-5-6x5= 10 + 6x3= 4-20-5-5 = 

XIV. MULTIPLICATION 



A. $0.03 
6 


$0.05 
11 


$0.06 
6 


$0.04 
11 


$0.05 
8 


$0.04 
6 


B. $0.07 
11 


$0.05 
6 


$0.06 
11 


$0.03 
8 


$0.08 
11 


$0.05 
9 


a $0.03 
9 


$0.05 

7 


$0.09 
11 


$0.03 
12 


$0.04 
8 


$0.10 
10 


D. $0.04 
12 


$0.09 
9 


$0.07 

7 


$0.05 
12 


$0.06 

7 


$0.04 
9 



XV. MULTIPLICATION 

A. $0.06x8= $0.06x12= $0.08x8= $0.06x9 = 

B. $0.09x12= $0.08x9= $0.12x12= $0.07x8 = 
a $0.07x12= $0.07x9= $0.08x12= $0.10x12 = 

D. $0.10x11= $0.11x12= $0.11x11= $0.09x8 = 

E. $0.12x11= $0.11x10= $0.12x10= $0.09x7 = 

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GRADE IV. FOURTH SERIES 109 

XVI. PROBLEMS OF THE DAIRY 

1. If Mr. Jones has 4 cows, each of which gives 12 
quarts of milk a day, how many gallons of milk do 
they give? (This may be done in two ways. Which is 
the easier?) 

2. If one of Mr. Jones's cows gives 13 quarts of milk 
a day, and he keeps 3 quarts for family use, how many 
customers can he supply with 2 quarts each? 

3. Mr. Jones feeds daily 5 quarts of skim milk to each 
of 3 pigs. In 10 days the pigs will drink quarts. 

4. If a milkman sells cream for $0.20 a half pint, 
how much will Mrs. Mathews pay him if she buys 
half a pint each week for a month? 

5. If milk is $0.09 a pint, how much is it a quart? 
a gallon? (The last part may be done in two ways.) 

6. Mr. Jones sells milk to a milkman for $0.06 a 
quart in large cans containing 9 quarts. How much 
does he receive per large can? 

. 7. If a farmer pays to an expressman $0.04 a can to 
take his milk to the railroad station, where it is shipped 
to the city, it will cost him to send 11 cans. 

8. Mr. Jones puts up some of his milk in quart bottles. 

If each bottle costs $0.05, he will pay for a dozen 

bottles. If one of the dozen is broken and he buys an 
extra bottle to take its place, he will pay for bottles. 

Additional Work. Each pupil should write out and bring to class 
a similar problem of his own. 

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110 PRACTICE EXEECISES IN MENTAL AEITHMETIC 

XVII. FRACTIONAL PARTS WITH REMAINDERS 

Note. Pupils may state the remainders as whole numbers or as frac- 
tions, as the teacher may direct; that is, J of 5 = 2 and 1 over, or 2\. 

^. ^ of 3 = i of 7 = i of 9 = i of 11 = 

^. ^ of 4 = i of 7= ^ of 10 = ^ of 13 - 
C. J of 5 = J of 9 = J of 13 = 1 of 17 = 

XVIII. DIVISION WITH REMAINDERS 

Note. Have pupils state the nearest number of times the divisor is 
contained in the dividend, ignoring the exact remainder. This will give 
practice in finding trial divisors. Additional practice may be given with 
similar examples put on the board. 

A. 12)13 12)25 12)40 10)87 15)35 20)il 

B. 25)60 21)43 14)30 11)40 11)78 13)43 

C. 33)77 25)60 30)70 40)90 20)50 60)l30 

XIX. DIVISION WITH REMAINDERS 



A. 11)109 ll)l05 20)130 12)100 9)65 
5. 27)50 11)100 32)50 45)80 23)37 

a 28)60 26)49 52)90 58)l00 44)89 

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GRADE IV. FOURTH SERIES 111 
XX. PROBLEMS OF THE CARPENTER 

1. A carpenter often uses a two-foot rule. It is some- 
times divided into four parts, joined together by hinges. 
When the carpenter folds this measure once there are 
inches in each of the two parts. 

2. When the carpenter folds his two-foot measure twice, 

each of the four parts is inches long. (This may be 

done in two ways.) 

3. Nelson has a stick 15 inches long. He wants to cut 
off pieces 4 inches long. How many such pieces can he 
cut from his stick? (This can be done in two ways. 
Which is the quicker way?) 

4. Nelson has a stick 37 inches long. How can he use 
it for a yardstick ? (This can be done in two ways.) 

5. From a stick 1 inch wide and 11 inches long how 
many pieces containing 2 square inches can be cut? 

6. Mr. Harris, the carpenter, needs 6 screws for each of 
8 pairs of hinges that he is putting on some doors. He 
finds that he has 45 screws. Is that enough ? (You can 
do this in three ways. Select the easiest way.) 

7. Mr. Harris works 44 horns in a week. How many 
full days of 8 hours each does he work ? 

8. A package of screws contains a gross, but one screw 
is lost from a package. How many sets of screws of 
1 dozen in each set can be made up from this package ? 

Addttionql Work. Hack pupil should write out and bring to class 
a similar problem of his ounu 

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112 PBACTICE EXERCISES IN MENTAL ARITHMETIC 

XXI. FRACTIONAL PARTS WITH REMAINDERS 
A i of $0.13= ^ of 10.15= ^ of $0.17= i of 19 in. = 

A ^of22ft.= Jof25mi.= ^ofl4pt.= ^of28gal.= 

C. ^of 13oz.= Jof251b.= Jof7da.= Jof29yr.= 

XXII. DIVISION WITH REMAINDERS 

A. 13j$27 14)$29 15)$35 19)$39 ISjIlO 

B. $2lJ$40 $22)$50 $25)176 $30j$70 $40)|90 

C. 12)40iZ 15)33i^ 20)451; 50)75 yd. 80)170 mi. 

D. 8 oz.)25 oz. 11 lb.) 23 lb. 15 sec.) 33 sec. 14 cla.)26 da. 

XXIIL DIVISION WITH REMAINDERS 

A. 16)28 qt. 18)30 qt. 21)50 pt. 33)67 gi. 19)40 gal. 

B. 22 qt.)41 qt. 33 gi.)65 gi. llgi.)75gi. 50pt.)99pt. 
a 4)17 doz. 14)27 doz. 17)30 gr. 44)90 quires 
2). 24 doz.) 55 doz. 39gr.)77gr. 44)90 quires 
^. 60)500 sheets 60 sheets) 500 sheets 

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GRADE IV. FOURTH SERIES 118 

XXIV. PROBLEMS OF THE FARMER 

1. Mr. Wilbur is a farmer living 13 miles from a 
large dty. About ^ of the way to the city is the 

nearest village, which is therefore about miles 

from Mr. Wilbur's home. 

2. If Mr. Wilbur's hens lay 50 eggs in one day he 
has full dozen to sell. 

3. If at another time Mt. Wilbur receives from a 
peddler $1.50 for eggs that are selling for $0.60 a 
dozen, he must have sold more than dozen. 

4. In a large can Mr. Wilbur has 21 quarts of milk. 

He pours it into two-quart bottles. He fills bottles 

and has quart, or bottle left over. 

5. If Mr. Wilbur chums 17 pounds of butter and 
puts it into 5-pound boxes, he has boxes of butter. 

6. In the month of June there are days. This 

is weeks and days. 

7. In Mr. Wilbur's bam the place where the cows 
stand (the stanchions) is 43 feet long. If it is divided 
up so that each cow has 4 feet of space in which to 
stand, he can put cows in the stanchions. 

8. Mr. Wilbur weighs out 19 pounds of com meal. 
He makes it into a mash for his hens and chickens. 
He has 4 pens of hens. To each pen he gives the 
same amount of mash, and the rest he gives to his 

chickens. Then he gives pounds to each pen of 

hens and pounds to his chickens. 

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114 PRACTICE EXERCISES IN MENTAL ARITHMETIC 

XXV. PROBLEMS: MISCELLANEOUS 

1. Mr. Sands drives an ice wagon. During July he 
worked 26 days. How many days did he **take off" 
in July? 

2. One cake of ice weighs 25 pounds, but Mrs. Howe 

wants only 15 pounds, so Mr. Sands must cut off 

pounds. 

3. Harry lives on a farm. One day he opens a new 
2-bushel bag of com. How many quarts were in the 
bag? (Do this in two ways-) 

4. Harry pours ^ the bag of com into a box. How 
many feedings will this be for the horse if he "gives 
the horse 4 quarts at a time? 

5. Sam buys 2 balls of twine, each containing 150 feet. 
He ties the two balls together for a kite string. His string 
is then feet long. (Do this in two ways.) 

6. Three boys are playing ball in the school yard. The 
ball accidentally breaks a window that costs $0.75 to re- 
place. Each boy should pay . (Do this in two ways.) 

7. Dick generally spends 25 minutes studying his 
daily spelling lesson. If by studying hard he can 
learn it in 15 minutes, how much time would he gain 
in 6 days by studying hard? 

8. The teacher has a box of 45 pencils. She asks 5 
boys to sharpen them for her. If each boy takes the 
same number, how many will he sharpen? 

9. If 4 other boys help the 5 boys sharpen the 45 
pencils, each will sharpen pencils. 

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GRADE IV. FOURTH SERIES 115 

XXVI. PROBLEMS: MISCELLANEOUS 

1. In Sarah's school the children agree with the teacher 
to spend 6 minutes a day in ** housekeeping" ; that is, in 
helping keep the schoolroom neat and clean. How many 
minutes does each pupil spend in this way during a school 
week? This amounts to hours in a fortnight. 

2. Mrs. Thomas buys a handkerchief for $0.35 and a 
yard of ribbon for $0.22. She passes the clerk $0.75. 
Count out her change. 

3. A coal dealer buys coal from the mines for $9.10 
a ton. He sells a ton to Mrs. Sampson for $11.25. How 
much does the dealer make? Is this all profit? 

4. Henry and James are measuring two di£Eerent strips 
of wood. Henry says that his stick measures IJ feet. 
James says his measures 18 inches. Which is longer, and 
how much ? (Can you do this in two ways ?) 

5. Harold earns money by doing odd jobs out of school. 
A neighbor pays him at the rate of $0.15 an hour. If he 
works only 30 minutes he should receive . 

6. Harold works 20 minutes a day for 3 days. If 
he receives $0.15 an horn*, how much should he receive 
for his three days' work? (Do this in two ways.) 

7. Mrs. Hart has 5 yards of cloth that she wishes to 
make into aprons for 4 little girls. If she uses all the cloth 
and makes all the aprons of the same size, how much cloth ; 
will be used for each apron ? (Do this in two ways.) 

AdditUmal Work. Each pupil should write out and bring to class 
a similar problem of his own. 

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